/**
 * Audio Converter Page - Premium Black & Gold Theme
 * 深海鎏金主题 - 内页优化版 v2.0
 * v2.0 - 2026-01-14 - 同步首页顶奢风格
 */

/* ===== CSS Variables ===== */
:root {
  --ac-bg-page: #050A14;
  --ac-gold-primary: #D4AF37;
  --ac-gold-light: #F3E6C4;
  --ac-gold-dark: #B8960B;
  --ac-text-primary: #FFFFFF;
  --ac-text-secondary: #C5D2E0;
  --ac-text-muted: #8A99AB;
  --ac-border-subtle: rgba(255, 255, 255, 0.06);
  --ac-border-default: rgba(255, 255, 255, 0.1);
  --ac-border-gold: rgba(212, 175, 55, 0.4);
}

/* ===== 1. Premium Breadcrumb Navigation (玻璃态胶囊) ===== */
.ac-breadcrumb-nav {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(12px);
  border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.ac-breadcrumb-nav li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.ac-breadcrumb-nav a {
  color: #999;
  font-size: 0.875rem;
  transition: color 0.2s ease;
  text-decoration: none;
}

.ac-breadcrumb-nav a:hover {
  color: var(--ac-gold-primary);
}

.ac-breadcrumb-nav .ac-breadcrumb-separator {
  color: rgba(212, 175, 55, 0.5);
  font-size: 0.75rem;
}

.ac-breadcrumb-nav .ac-breadcrumb-current {
  color: var(--ac-gold-primary);
  font-weight: 500;
  font-size: 0.875rem;
}

/* ===== 2. Feature Chips (特性标签 - 黑金化) ===== */
.ac-feature-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  background: transparent;
  border: 1px solid rgba(212, 175, 55, 0.4);
  border-radius: 50px;
  font-size: 0.875rem;
  color: var(--ac-text-secondary);
  transition: all 0.3s ease;
}

.ac-feature-chip:hover {
  border-color: var(--ac-gold-primary);
  background: rgba(212, 175, 55, 0.08);
  color: var(--ac-gold-light);
}

.ac-feature-chip .material-symbols-outlined {
  font-size: 1.125rem;
  color: var(--ac-gold-primary);
}

/* ===== Hero Section Enhancement ===== */
.ac-hero-section {
  position: relative;
  padding: 3rem 0 2rem;
  text-align: center;
}

/* 顶部金色光晕背景 */
.ac-hero-section::before {
  content: '';
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 500px;
  background: radial-gradient(
    ellipse 60% 40% at 50% 30%,
    rgba(212, 175, 55, 0.12) 0%,
    rgba(212, 175, 55, 0.05) 40%,
    transparent 70%
  );
  pointer-events: none;
  z-index: 0;
}

.ac-hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
  position: relative;
  z-index: 1;
}

.ac-hero-desc {
  font-size: 1.25rem;
  color: var(--ac-text-secondary);
  max-width: 640px;
  margin: 0 auto 1.5rem;
  position: relative;
  z-index: 1;
}

/* ===== Premium Upload Area ===== */
.ac-upload-container {
  position: relative;
  max-width: 900px;
  margin: 0 auto 4rem;
}

/* 上传区域背后的金色光晕 */
.ac-upload-container::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120%;
  height: 150%;
  background: radial-gradient(
    ellipse 50% 50% at 50% 50%,
    rgba(212, 175, 55, 0.08) 0%,
    rgba(212, 175, 55, 0.03) 40%,
    transparent 70%
  );
  pointer-events: none;
  z-index: 0;
}

.ac-upload-area {
  position: relative;
  z-index: 1;
  min-height: 380px;
  padding: 3rem 2rem;
  border-radius: 24px;
  background: linear-gradient(
    145deg,
    rgba(255, 255, 255, 0.04) 0%,
    rgba(0, 0, 0, 0.2) 100%
  );
  backdrop-filter: blur(20px);
  /* Animated dash border using SVG background */
  border: 2px dashed rgba(212, 175, 55, 0.4);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  cursor: pointer;
}

/* Add subtle animated glow border effect */
.ac-upload-area::before {
  content: '';
  position: absolute;
  inset: -2px;
  border-radius: 26px;
  background: linear-gradient(90deg,
    transparent 0%,
    rgba(212, 175, 55, 0.3) 25%,
    rgba(255, 215, 0, 0.5) 50%,
    rgba(212, 175, 55, 0.3) 75%,
    transparent 100%
  );
  background-size: 200% 100%;
  z-index: -1;
  opacity: 0;
  transition: opacity 0.4s ease;
  animation: ac-border-flow 3s linear infinite;
}

@keyframes ac-border-flow {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

.ac-upload-area:hover::before {
  opacity: 1;
}

.ac-upload-area:hover {
  border-color: rgba(212, 175, 55, 0.7);
  border-style: solid;
  background: linear-gradient(
    145deg,
    rgba(255, 255, 255, 0.06) 0%,
    rgba(212, 175, 55, 0.05) 100%
  );
  box-shadow:
    0 0 60px rgba(212, 175, 55, 0.15),
    0 20px 40px rgba(0, 0, 0, 0.3);
  transform: translateY(-4px);
}

.ac-upload-area.drag-over {
  border-color: var(--ac-gold-primary);
  border-style: solid;
  background: rgba(212, 175, 55, 0.1);
  box-shadow: 0 0 80px rgba(212, 175, 55, 0.25);
}

.ac-upload-area.drag-over::before {
  opacity: 1;
}

/* 上传图标容器 */
.ac-upload-icon-wrapper {
  position: relative;
  width: 120px;
  height: 120px;
  margin: 0 auto 2rem;
}

.ac-upload-icon-glow {
  position: absolute;
  inset: -20px;
  background: radial-gradient(
    circle at 50% 50%,
    rgba(212, 175, 55, 0.25) 0%,
    transparent 70%
  );
  border-radius: 50%;
  filter: blur(20px);
  animation: ac-pulse 3s ease-in-out infinite;
}

@keyframes ac-pulse {
  0%, 100% { opacity: 0.5; transform: scale(1); }
  50% { opacity: 0.8; transform: scale(1.1); }
}

.ac-upload-icon-ring {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: linear-gradient(
    135deg,
    rgba(212, 175, 55, 0.15) 0%,
    rgba(243, 230, 196, 0.08) 100%
  );
  border: 2px solid rgba(212, 175, 55, 0.4);
  box-shadow:
    0 0 30px rgba(212, 175, 55, 0.2),
    inset 0 0 20px rgba(212, 175, 55, 0.1);
}

.ac-upload-icon-ring .material-symbols-outlined {
  font-size: 56px;
  background: linear-gradient(180deg, #FFFAF0 0%, #FFD700 40%, #D4AF37 70%, #B8860B 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 4px 8px rgba(212, 175, 55, 0.4));
}

/* 上传按钮 */
.ac-upload-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 2.5rem;
  font-size: 1.125rem;
  font-weight: 600;
  color: #050A14;
  background: linear-gradient(90deg, #D4AF37 0%, #F3E6C4 50%, #D4AF37 100%);
  background-size: 200% auto;
  border: none;
  border-radius: 50px;
  cursor: pointer;
  box-shadow:
    0 4px 20px rgba(212, 175, 55, 0.4),
    0 0 40px rgba(212, 175, 55, 0.2);
  transition: all 0.3s ease;
}

.ac-upload-btn:hover {
  background-position: right center;
  transform: translateY(-2px);
  box-shadow:
    0 8px 30px rgba(212, 175, 55, 0.5),
    0 0 60px rgba(212, 175, 55, 0.3);
}

/* ===== How It Works - Visual Steps (首页同款顶奢风格) ===== */
.ac-steps-section {
  padding: 5rem 0;
  position: relative;
}

.ac-section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.ac-section-title {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.ac-section-desc {
  font-size: 1.125rem;
  color: var(--ac-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.ac-steps-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  max-width: 1100px;
  margin: 0 auto;
  position: relative;
}

@media (min-width: 768px) {
  .ac-steps-container {
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
  }
}

/* 连接线 - 动态光流 (首页同款) */
.ac-steps-line {
  display: none;
}

@media (min-width: 768px) {
  .ac-steps-line {
    display: block;
    position: absolute;
    top: 52px; /* Align with center of icons */
    left: 10%;
    right: 10%;
    height: 2px;
    /* Base line - subtle gold gradient fade on both ends */
    background: linear-gradient(90deg,
      transparent 0%,
      rgba(212, 175, 55, 0.15) 15%,
      rgba(212, 175, 55, 0.25) 50%,
      rgba(212, 175, 55, 0.15) 85%,
      transparent 100%
    );
    border-radius: 2px;
    z-index: 0;
    overflow: visible;
  }

  /* Animated light pulse traveling along the line */
  .ac-steps-line::before {
    content: '';
    position: absolute;
    top: -3px;
    left: 0;
    width: 80px;
    height: 8px;
    background: radial-gradient(ellipse at center,
      rgba(255, 215, 0, 0.9) 0%,
      rgba(212, 175, 55, 0.6) 30%,
      rgba(212, 175, 55, 0.2) 60%,
      transparent 100%
    );
    border-radius: 50%;
    filter: blur(2px);
    animation: ac-energy-flow 3s ease-in-out infinite;
  }

  /* Secondary trailing glow */
  .ac-steps-line::after {
    content: '';
    position: absolute;
    top: -1px;
    left: 0;
    width: 40px;
    height: 4px;
    background: linear-gradient(90deg,
      transparent 0%,
      #FFD700 50%,
      transparent 100%
    );
    border-radius: 2px;
    animation: ac-energy-flow 3s ease-in-out infinite;
    animation-delay: 0.1s;
  }
}

/* Energy flow animation */
@keyframes ac-energy-flow {
  0% {
    left: -10%;
    opacity: 0;
  }
  10% {
    opacity: 1;
  }
  90% {
    opacity: 1;
  }
  100% {
    left: 100%;
    opacity: 0;
  }
}

/* 步骤卡片 - 首页同款spotlight效果 */
.ac-step-card {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 1.5rem 1rem;
  border-radius: 20px;
  background: radial-gradient(
    ellipse 100% 100% at 50% 0%,
    rgba(212, 175, 55, 0.04) 0%,
    transparent 70%
  );
  transition: all 0.3s ease;
}

.ac-step-card:hover {
  background: radial-gradient(
    ellipse 100% 100% at 50% 0%,
    rgba(212, 175, 55, 0.08) 0%,
    transparent 70%
  );
}

/* 步骤图标 - 玻璃金边风格 (无实心填充) */
.ac-step-icon {
  width: 80px;
  height: 80px;
  margin: 0 auto 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 20px;
  /* Glass fill effect - subtle gold interior */
  background:
    linear-gradient(145deg,
      rgba(255, 215, 0, 0.08) 0%,
      rgba(212, 175, 55, 0.04) 50%,
      rgba(255, 215, 0, 0.08) 100%
    ),
    rgba(255, 215, 0, 0.05);
  /* Solid gold border */
  border: 1.5px solid rgba(212, 175, 55, 0.55);
  box-shadow:
    0 0 12px rgba(212, 175, 55, 0.15),
    inset 0 1px 0 rgba(255, 215, 0, 0.1);
  position: relative;
  transition: all 0.3s ease;
}

/* 图标背后光晕 */
.ac-step-icon::before {
  content: '';
  position: absolute;
  inset: -4px;
  border-radius: 24px;
  background: radial-gradient(
    circle at 50% 50%,
    rgba(212, 175, 55, 0.15) 0%,
    transparent 70%
  );
  z-index: -1;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.ac-step-card:hover .ac-step-icon {
  border-color: rgba(212, 175, 55, 0.7);
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(212, 175, 55, 0.2);
}

.ac-step-card:hover .ac-step-icon::before {
  opacity: 1;
}

.ac-step-icon .material-symbols-outlined {
  font-size: 36px;
  /* Thinner stroke for sharper look */
  font-variation-settings: 'wght' 300, 'GRAD' 0;
  background: linear-gradient(180deg,
    #FFFAF0 0%,
    #FFD700 40%,
    #D4AF37 70%,
    #B8860B 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 2px 4px rgba(212, 175, 55, 0.3));
}

.ac-step-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--ac-text-primary);
  margin-bottom: 0.5rem;
}

.ac-step-desc {
  font-size: 0.875rem;
  color: #C0C0C0;
  line-height: 1.6;
}

/* ===== Premium Intro Accordion (黑金手风琴) ===== */
.ac-intro-section {
  padding: 5rem 0;
  position: relative;
}

.ac-intro-container {
  max-width: 900px;
  margin: 0 auto;
}

.ac-intro-header {
  text-align: center;
  margin-bottom: 3rem;
}

.ac-intro-title {
  font-size: 2.25rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.ac-intro-desc {
  font-size: 1.125rem;
  color: var(--ac-text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.ac-accordion-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

/* Accordion Item - Premium Glass Style */
.ac-accordion-item {
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  overflow: hidden;
  transition: all 0.3s ease;
}

.ac-accordion-item:hover {
  border-color: rgba(212, 175, 55, 0.25);
  background: rgba(255, 255, 255, 0.03);
}

.ac-accordion-item[open] {
  background: rgba(212, 175, 55, 0.03);
  border-color: rgba(212, 175, 55, 0.35);
  box-shadow:
    0 8px 32px rgba(0, 0, 0, 0.2),
    0 0 20px rgba(212, 175, 55, 0.08);
}

/* Accordion Header/Summary */
.ac-accordion-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  cursor: pointer;
  list-style: none;
  transition: all 0.3s ease;
}

.ac-accordion-header::-webkit-details-marker {
  display: none;
}

.ac-accordion-header:hover {
  background: rgba(212, 175, 55, 0.05);
}

/* Accordion Icon Container */
.ac-accordion-icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.12) 0%,
    rgba(212, 175, 55, 0.05) 100%
  );
  border: 1px solid rgba(212, 175, 55, 0.3);
  transition: all 0.3s ease;
}

.ac-accordion-item[open] .ac-accordion-icon {
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.2) 0%,
    rgba(212, 175, 55, 0.08) 100%
  );
  border-color: rgba(212, 175, 55, 0.5);
  box-shadow: 0 0 15px rgba(212, 175, 55, 0.2);
}

.ac-accordion-icon .material-symbols-outlined {
  font-size: 22px;
  background: linear-gradient(180deg, #FFD700 0%, #D4AF37 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Accordion Title & Arrow */
.ac-accordion-title-wrap {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.ac-accordion-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--ac-text-primary);
  transition: color 0.3s ease;
}

.ac-accordion-item[open] .ac-accordion-title {
  color: var(--ac-gold-light);
}

.ac-accordion-arrow {
  flex-shrink: 0;
  font-size: 1.25rem;
  color: rgba(212, 175, 55, 0.6);
  transition: all 0.3s ease;
}

.ac-accordion-item[open] .ac-accordion-arrow {
  transform: rotate(180deg);
  color: var(--ac-gold-primary);
}

/* Accordion Content */
.ac-accordion-content {
  padding: 0 1.5rem 1.5rem 4.5rem;
  font-size: 0.95rem;
  color: var(--ac-text-secondary);
  line-height: 1.7;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  margin-top: -0.25rem;
  padding-top: 1rem;
}

.ac-accordion-content ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.ac-accordion-content li {
  position: relative;
  padding-left: 1.25rem;
  color: var(--ac-text-secondary);
}

.ac-accordion-content li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--ac-gold-primary), var(--ac-gold-light));
}

.ac-accordion-content strong {
  color: var(--ac-text-primary);
}

.ac-accordion-content a {
  color: var(--ac-gold-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
  transition: color 0.2s ease;
}

.ac-accordion-content a:hover {
  color: var(--ac-gold-light);
}

/* Copyright Notice at bottom */
.ac-intro-footer {
  margin-top: 2rem;
  padding: 1.25rem 1.5rem;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  font-size: 0.9rem;
  color: var(--ac-text-muted);
}

.ac-intro-footer strong {
  color: var(--ac-text-primary);
}

/* ===== Features Grid - Premium Glass Outline (黑金玻璃卡片) ===== */
.ac-features-section {
  padding: 5rem 0;
  position: relative;
  overflow: hidden;
}

/* Background ambiance - Large central gold glow */
.ac-features-section::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 1200px;
  height: 800px;
  background: radial-gradient(
    ellipse 60% 50% at 50% 50%,
    rgba(212, 175, 55, 0.08) 0%,
    rgba(212, 175, 55, 0.04) 30%,
    transparent 70%
  );
  pointer-events: none;
  z-index: 0;
}

/* Secondary ambient glow - right side */
.ac-features-section::after {
  content: '';
  position: absolute;
  top: 30%;
  right: -5%;
  width: 600px;
  height: 600px;
  background: radial-gradient(
    circle at center,
    rgba(212, 175, 55, 0.06) 0%,
    transparent 60%
  );
  pointer-events: none;
  z-index: 0;
}

.ac-features-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  max-width: 1100px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

@media (min-width: 640px) {
  .ac-features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .ac-features-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Premium Glass Outline Card */
.ac-feature-card {
  position: relative;
  padding: 2.5rem 1.75rem;
  border-radius: 24px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: hidden;
}

/* Subtle inner glow on hover */
.ac-feature-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: 24px;
  background: radial-gradient(
    ellipse 80% 60% at 50% 0%,
    rgba(212, 175, 55, 0.08) 0%,
    transparent 60%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

.ac-feature-card:hover {
  border-color: rgba(212, 175, 55, 0.4);
  transform: translateY(-6px);
  box-shadow:
    0 20px 50px rgba(0, 0, 0, 0.25),
    0 0 30px rgba(212, 175, 55, 0.1);
}

.ac-feature-card:hover::before {
  opacity: 1;
}

/* Large Centered Floating Icon */
.ac-feature-icon {
  position: relative;
  width: 80px;
  height: 80px;
  margin: 0 auto 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 20px;
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.1) 0%,
    rgba(212, 175, 55, 0.03) 100%
  );
  border: 1.5px solid rgba(212, 175, 55, 0.35);
  box-shadow:
    0 8px 24px rgba(0, 0, 0, 0.15),
    0 0 15px rgba(212, 175, 55, 0.1);
  transition: all 0.4s ease;
}

/* Icon glow effect */
.ac-feature-icon::before {
  content: '';
  position: absolute;
  inset: -8px;
  border-radius: 28px;
  background: radial-gradient(
    circle at center,
    rgba(212, 175, 55, 0.2) 0%,
    transparent 70%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  z-index: -1;
}

.ac-feature-card:hover .ac-feature-icon {
  border-color: rgba(212, 175, 55, 0.6);
  transform: translateY(-4px);
  box-shadow:
    0 12px 30px rgba(0, 0, 0, 0.2),
    0 0 25px rgba(212, 175, 55, 0.2);
}

.ac-feature-card:hover .ac-feature-icon::before {
  opacity: 1;
}

.ac-feature-icon .material-symbols-outlined {
  font-size: 36px;
  font-variation-settings: 'wght' 300, 'GRAD' 0;
  background: linear-gradient(180deg,
    #FFFAF0 0%,
    #FFD700 40%,
    #D4AF37 70%,
    #B8860B 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 3px 6px rgba(212, 175, 55, 0.35));
}

.ac-feature-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--ac-text-primary);
  margin-bottom: 0.75rem;
  transition: color 0.3s ease;
}

.ac-feature-card:hover .ac-feature-title {
  color: var(--ac-gold-light);
}

.ac-feature-desc {
  font-size: 0.9rem;
  color: var(--ac-text-secondary);
  line-height: 1.7;
}

/* ===== Premium Floating Table Style (悬浮清单) ===== */
.ac-table-section {
  padding: 5rem 0;
}

.ac-table-container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0;
  border-radius: 24px;
  background: transparent;
  border: none;
  overflow: visible;
}

.ac-table-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.ac-table-header-icon {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.12) 0%,
    rgba(212, 175, 55, 0.05) 100%
  );
  border: 1px solid rgba(212, 175, 55, 0.3);
}

.ac-table-header-icon .material-symbols-outlined {
  font-size: 24px;
  background: linear-gradient(180deg, #FFD700 0%, #D4AF37 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.ac-premium-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
}

/* Table Header - Pure Black + Gold Text */
.ac-premium-table thead {
  background: #0A0E18;
}

.ac-premium-table th {
  padding: 1rem 1.25rem;
  text-align: left;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--ac-gold-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  /* Strong gold header border */
  border-bottom: 2px solid #D4AF37;
}

.ac-premium-table th:first-child {
  border-radius: 12px 0 0 0;
}

.ac-premium-table th:last-child {
  border-radius: 0 12px 0 0;
}

/* Table Body - Floating List Style */
.ac-premium-table tbody tr {
  transition: all 0.25s ease;
}

.ac-premium-table td {
  padding: 1.25rem 1.25rem;
  font-size: 0.9rem;
  color: var(--ac-text-secondary);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  background: transparent;
  transition: background 0.25s ease;
}

.ac-premium-table tbody tr:hover td {
  background: rgba(26, 26, 26, 0.8);
}

.ac-premium-table tr:last-child td {
  border-bottom: none;
}

.ac-premium-table tr:last-child td:first-child {
  border-radius: 0 0 0 12px;
}

.ac-premium-table tr:last-child td:last-child {
  border-radius: 0 0 12px 0;
}

/* Format Name - Gold Accent */
.ac-premium-table .ac-format-name {
  font-weight: 700;
  font-size: 0.95rem;
  background: linear-gradient(180deg, #FFD700 0%, #D4AF37 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.ac-premium-table .ac-highlight {
  color: var(--ac-gold-light);
  font-weight: 500;
}

/* Pill Badge for "Best For" column */
.ac-pill-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.4rem 0.85rem;
  margin: 0.15rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 50px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.15);
  color: var(--ac-text-secondary);
  transition: all 0.25s ease;
}

.ac-pill-badge:hover {
  border-color: rgba(212, 175, 55, 0.5);
  color: var(--ac-gold-light);
  background: rgba(212, 175, 55, 0.08);
}

/* Gold variant - primary use cases */
.ac-pill-badge.ac-pill-gold {
  border-color: rgba(212, 175, 55, 0.5);
  color: var(--ac-gold-primary);
  background: rgba(212, 175, 55, 0.1);
  box-shadow: 0 0 8px rgba(212, 175, 55, 0.15);
}

.ac-pill-badge.ac-pill-gold:hover {
  border-color: rgba(212, 175, 55, 0.7);
  box-shadow: 0 0 12px rgba(212, 175, 55, 0.25);
}

/* Type Badge */
.ac-type-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.35rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 500;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.ac-type-badge.lossy {
  color: #8A99AB;
}

.ac-type-badge.lossless {
  color: var(--ac-gold-light);
  border-color: rgba(212, 175, 55, 0.25);
  background: rgba(212, 175, 55, 0.08);
}

.ac-type-badge.hybrid {
  color: #F3E6C4;
  border-color: rgba(243, 230, 196, 0.2);
}

/* ===== Format Detail Cards - Bento Glass Style (玻璃态卡片) ===== */
.ac-format-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  margin-top: 3rem;
}

@media (min-width: 768px) {
  .ac-format-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.ac-format-card {
  position: relative;
  padding: 2rem;
  border-radius: 20px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.06);
  backdrop-filter: blur(8px);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: hidden;
}

/* Top gradient glow on hover */
.ac-format-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 100px;
  background: linear-gradient(180deg,
    rgba(212, 175, 55, 0.06) 0%,
    transparent 100%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

.ac-format-card:hover {
  border-color: rgba(212, 175, 55, 0.35);
  transform: translateY(-4px);
  box-shadow:
    0 20px 50px rgba(0, 0, 0, 0.25),
    0 0 30px rgba(212, 175, 55, 0.08);
}

.ac-format-card:hover::before {
  opacity: 1;
}

.ac-format-card-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1.25rem;
  position: relative;
  z-index: 1;
}

/* Large Gold Gradient Icon */
.ac-format-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 16px;
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.15) 0%,
    rgba(212, 175, 55, 0.05) 100%
  );
  border: 1.5px solid rgba(212, 175, 55, 0.4);
  box-shadow: 0 0 20px rgba(212, 175, 55, 0.15);
  transition: all 0.3s ease;
}

.ac-format-card:hover .ac-format-icon {
  border-color: rgba(212, 175, 55, 0.6);
  box-shadow: 0 0 30px rgba(212, 175, 55, 0.25);
}

.ac-format-icon .material-symbols-outlined {
  font-size: 28px;
  background: linear-gradient(180deg,
    #FFFAF0 0%,
    #FFD700 40%,
    #D4AF37 70%,
    #B8860B 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 2px 4px rgba(212, 175, 55, 0.3));
}

.ac-format-card-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--ac-text-primary);
}

.ac-format-card-body {
  position: relative;
  z-index: 1;
  font-size: 0.9rem;
  color: var(--ac-text-secondary);
  line-height: 1.7;
  margin-bottom: 1.25rem;
}

/* Pros/Cons List with Glowing Gold Checkmarks */
.ac-format-pros-cons {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.ac-format-pros-cons li {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-size: 0.875rem;
  color: var(--ac-text-secondary);
}

.ac-format-pros-cons .ac-check-icon {
  font-size: 18px;
  background: linear-gradient(180deg, #FFD700 0%, #D4AF37 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 6px rgba(212, 175, 55, 0.5));
}

.ac-format-pros-cons .ac-minus-icon {
  font-size: 18px;
  color: #6B7280;
}

/* ===== Use Case Cards - Gold Badge Style (场景推荐) ===== */
.ac-usecase-section {
  padding: 5rem 0;
  position: relative;
}

.ac-usecase-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  max-width: 1100px;
  margin: 0 auto;
}

@media (min-width: 640px) {
  .ac-usecase-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .ac-usecase-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.ac-usecase-card {
  position: relative;
  padding: 2rem 1.75rem;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
}

.ac-usecase-card:hover {
  transform: translateY(-6px);
  border-color: rgba(212, 175, 55, 0.35);
  box-shadow:
    0 20px 50px rgba(0, 0, 0, 0.25),
    0 12px 30px rgba(212, 175, 55, 0.1);
}

/* Large Centered Icon */
.ac-usecase-icon {
  width: 64px;
  height: 64px;
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 18px;
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.12) 0%,
    rgba(212, 175, 55, 0.04) 100%
  );
  border: 1px solid rgba(212, 175, 55, 0.3);
  transition: all 0.3s ease;
}

.ac-usecase-card:hover .ac-usecase-icon {
  border-color: rgba(212, 175, 55, 0.5);
  box-shadow: 0 0 25px rgba(212, 175, 55, 0.2);
  transform: translateY(-2px);
}

.ac-usecase-icon .material-symbols-outlined {
  font-size: 30px;
  background: linear-gradient(180deg,
    #FFFAF0 0%,
    #FFD700 40%,
    #D4AF37 70%,
    #B8860B 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 2px 4px rgba(212, 175, 55, 0.3));
}

.ac-usecase-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ac-text-primary);
  margin-bottom: 0.75rem;
}

.ac-usecase-desc {
  font-size: 0.875rem;
  color: var(--ac-text-secondary);
  line-height: 1.6;
  margin-bottom: 1rem;
  flex: 1;
}

.ac-usecase-reason {
  font-size: 0.8rem;
  color: var(--ac-text-muted);
  margin-bottom: 1rem;
}

/* Gold Recommendation Badge */
.ac-recommend-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.625rem 1rem;
  border-radius: 50px;
  background: linear-gradient(135deg,
    rgba(212, 175, 55, 0.15) 0%,
    rgba(212, 175, 55, 0.08) 100%
  );
  border: 1px solid rgba(212, 175, 55, 0.4);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--ac-gold-primary);
  margin-top: auto;
  transition: all 0.3s ease;
}

.ac-usecase-card:hover .ac-recommend-badge {
  background: linear-gradient(135deg,
    rgba(212, 175, 55, 0.25) 0%,
    rgba(212, 175, 55, 0.12) 100%
  );
  border-color: rgba(212, 175, 55, 0.6);
  box-shadow: 0 0 15px rgba(212, 175, 55, 0.2);
}

.ac-recommend-badge .material-symbols-outlined {
  font-size: 16px;
  color: var(--ac-gold-primary);
}

/* ===== Bitrate Section - Visual Progress Bars (可视化进度条) ===== */
.ac-bitrate-section {
  padding: 3rem 0;
}

.ac-bitrate-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 2.5rem;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.ac-bitrate-title {
  font-size: 1.75rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 1rem;
}

.ac-bitrate-desc {
  text-align: center;
  font-size: 1rem;
  color: var(--ac-text-secondary);
  max-width: 600px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

/* Visual Progress Bar Grid */
.ac-bitrate-bars {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.ac-bitrate-item {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.ac-bitrate-label {
  min-width: 100px;
  text-align: right;
}

.ac-bitrate-value {
  font-size: 1.25rem;
  font-weight: 700;
}

.ac-bitrate-value.high {
  background: linear-gradient(180deg, #FFD700 0%, #D4AF37 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.ac-bitrate-value.medium {
  color: var(--ac-gold-light);
}

.ac-bitrate-value.low {
  color: #8A99AB;
}

.ac-bitrate-quality {
  font-size: 0.75rem;
  color: var(--ac-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Progress Bar Track */
.ac-bitrate-bar-track {
  flex: 1;
  height: 12px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.05);
  overflow: hidden;
  position: relative;
}

/* Progress Bar Fill */
.ac-bitrate-bar-fill {
  height: 100%;
  border-radius: 6px;
  transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

.ac-bitrate-bar-fill.high {
  width: 100%;
  background: linear-gradient(90deg,
    #B8860B 0%,
    #D4AF37 30%,
    #FFD700 60%,
    #FFFAF0 100%
  );
  box-shadow: 0 0 15px rgba(212, 175, 55, 0.5);
}

.ac-bitrate-bar-fill.medium {
  width: 60%;
  background: linear-gradient(90deg,
    #8B7355 0%,
    #B8960B 50%,
    #D4AF37 100%
  );
  box-shadow: 0 0 10px rgba(212, 175, 55, 0.3);
}

.ac-bitrate-bar-fill.low {
  width: 40%;
  background: linear-gradient(90deg,
    #4A5568 0%,
    #718096 50%,
    #A0AEC0 100%
  );
}

/* Bitrate Description */
.ac-bitrate-item-desc {
  min-width: 140px;
  font-size: 0.85rem;
  color: var(--ac-text-secondary);
}

/* Pro Tip Box */
.ac-pro-tip {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  border-radius: 16px;
  background: linear-gradient(135deg,
    rgba(212, 175, 55, 0.08) 0%,
    rgba(212, 175, 55, 0.03) 100%
  );
  border: 1px solid rgba(212, 175, 55, 0.2);
  margin-top: 1.5rem;
}

.ac-pro-tip-icon {
  width: 40px;
  height: 40px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: rgba(212, 175, 55, 0.15);
  border: 1px solid rgba(212, 175, 55, 0.3);
}

.ac-pro-tip-icon .material-symbols-outlined {
  font-size: 20px;
  color: var(--ac-gold-primary);
}

.ac-pro-tip-content {
  flex: 1;
}

.ac-pro-tip-title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ac-gold-light);
  margin-bottom: 0.25rem;
}

.ac-pro-tip-desc {
  font-size: 0.875rem;
  color: var(--ac-text-secondary);
  line-height: 1.6;
}

/* ===== FAQ Accordion - Minimalist Divider Style (极简分割线) ===== */
.ac-faq-section {
  padding: 5rem 0;
}

.ac-faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0;
}

/* Minimalist FAQ Item - No background, divider lines */
.ac-faq-item {
  border-radius: 0;
  background: transparent;
  border: none;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  overflow: hidden;
  transition: all 0.3s ease;
}

.ac-faq-item:first-child {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.ac-faq-item:hover {
  border-color: rgba(212, 175, 55, 0.2);
}

.ac-faq-item[open] {
  background: transparent;
  border-color: rgba(212, 175, 55, 0.25);
}

/* FAQ Question - Larger, brighter */
.ac-faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem 0.5rem;
  font-size: 1.125rem;
  font-weight: 500;
  color: #FFFFFF;
  cursor: pointer;
  list-style: none;
  transition: color 0.3s ease;
}

.ac-faq-question::-webkit-details-marker {
  display: none;
}

.ac-faq-question:hover {
  color: var(--ac-gold-light);
}

/* Gold Plus Icon */
.ac-faq-toggle {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: rgba(212, 175, 55, 0.1);
  border: 1px solid rgba(212, 175, 55, 0.3);
  flex-shrink: 0;
  transition: all 0.3s ease;
}

.ac-faq-toggle .material-symbols-outlined {
  font-size: 20px;
  color: var(--ac-gold-primary);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.ac-faq-item:hover .ac-faq-toggle {
  background: rgba(212, 175, 55, 0.15);
  border-color: rgba(212, 175, 55, 0.5);
}

.ac-faq-item[open] .ac-faq-toggle {
  background: rgba(212, 175, 55, 0.2);
  border-color: rgba(212, 175, 55, 0.6);
  box-shadow: 0 0 12px rgba(212, 175, 55, 0.25);
}

.ac-faq-item[open] .ac-faq-toggle .material-symbols-outlined {
  transform: rotate(45deg);
}

/* FAQ Answer - Fade in animation */
.ac-faq-answer {
  padding: 0 0.5rem 1.75rem 0.5rem;
  font-size: 1rem;
  color: rgba(200, 200, 210, 0.85);
  line-height: 1.7;
  border-top: none;
  margin-top: 0;
  padding-top: 0;
  animation: faqFadeIn 0.3s ease-out;
}

@keyframes faqFadeIn {
  from {
    opacity: 0;
    transform: translateY(-8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== More Tools - Premium Glass Bento Cards (高级玻璃卡片) ===== */
.ac-tools-section {
  padding: 5rem 0;
}

.ac-tools-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  max-width: 1000px;
  margin: 0 auto;
}

@media (min-width: 640px) {
  .ac-tools-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .ac-tools-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Premium Glass Tool Card */
.ac-tool-card {
  position: relative;
  display: flex;
  flex-direction: column;
  padding: 2rem 1.75rem;
  border-radius: 20px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.06);
  text-decoration: none;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: hidden;
}

/* Top gradient glow on hover */
.ac-tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: linear-gradient(180deg,
    rgba(212, 175, 55, 0.08) 0%,
    transparent 100%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  pointer-events: none;
}

.ac-tool-card:hover {
  background: rgba(212, 175, 55, 0.02);
  border-color: rgba(212, 175, 55, 0.4);
  transform: translateY(-6px);
  box-shadow:
    0 20px 50px rgba(0, 0, 0, 0.25),
    0 0 30px rgba(212, 175, 55, 0.1);
}

.ac-tool-card:hover::before {
  opacity: 1;
}

/* Large Premium Icon Container */
.ac-tool-icon {
  position: relative;
  width: 64px;
  height: 64px;
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 18px;
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.12) 0%,
    rgba(212, 175, 55, 0.04) 100%
  );
  border: 1.5px solid rgba(212, 175, 55, 0.35);
  box-shadow: 0 0 20px rgba(212, 175, 55, 0.1);
  transition: all 0.4s ease;
}

/* Icon glow effect */
.ac-tool-icon::before {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 24px;
  background: radial-gradient(
    circle at center,
    rgba(212, 175, 55, 0.2) 0%,
    transparent 70%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  z-index: -1;
}

.ac-tool-card:hover .ac-tool-icon {
  border-color: rgba(212, 175, 55, 0.6);
  transform: translateY(-3px);
  box-shadow:
    0 8px 25px rgba(0, 0, 0, 0.2),
    0 0 30px rgba(212, 175, 55, 0.2);
}

.ac-tool-card:hover .ac-tool-icon::before {
  opacity: 1;
}

.ac-tool-icon .material-symbols-outlined {
  font-size: 30px;
  font-variation-settings: 'wght' 300, 'GRAD' 0;
  background: linear-gradient(180deg,
    #FFFAF0 0%,
    #FFD700 40%,
    #D4AF37 70%,
    #B8860B 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 2px 4px rgba(212, 175, 55, 0.3));
}

/* Legacy icon support (header style) */
.ac-tool-card-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
}

.ac-tool-card-header .material-symbols-outlined {
  font-size: 1.75rem;
  background: linear-gradient(180deg, #FFD700 0%, #D4AF37 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 1px 2px rgba(212, 175, 55, 0.3));
}

.ac-tool-card-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ac-text-primary);
  transition: color 0.3s ease;
}

.ac-tool-card:hover .ac-tool-card-title {
  color: var(--ac-gold-light);
}

.ac-tool-card-desc {
  font-size: 0.9rem;
  color: var(--ac-text-secondary);
  line-height: 1.6;
  margin-top: auto;
}

/* ===== 2-Column Split Layout for Intro Section ===== */
.ac-intro-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  max-width: 100%;
}

@media (min-width: 1024px) {
  .ac-intro-split {
    grid-template-columns: 38% 58%;
    gap: 4%;
    align-items: center; /* Center align vertically */
  }
}

.ac-intro-left {
  /* Remove sticky for center alignment */
}

.ac-intro-left .ac-intro-title {
  text-align: left;
  font-size: 2rem;
  line-height: 1.2;
  margin-bottom: 1.25rem;
}

.ac-intro-left .ac-intro-desc {
  text-align: left;
  margin: 0;
  font-size: 1rem;
  color: var(--ac-text-secondary);
  line-height: 1.7;
}

/* Trust badges and CTA */
.ac-intro-trust {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.ac-intro-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: #D4AF37;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: all 0.3s ease;
}

.ac-intro-cta:hover {
  color: #FFD700;
  gap: 0.75rem;
}

.ac-intro-cta .material-symbols-outlined {
  font-size: 20px;
  transition: transform 0.3s ease;
}

.ac-intro-cta:hover .material-symbols-outlined {
  transform: translateX(4px);
}

.ac-intro-rating {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.ac-rating-stars {
  display: flex;
  gap: 2px;
}

.ac-rating-stars .material-symbols-outlined {
  font-size: 18px;
  color: #D4AF37;
  filter: drop-shadow(0 0 4px rgba(212, 175, 55, 0.4));
}

.ac-rating-text {
  font-size: 0.85rem;
  color: var(--ac-text-secondary);
}

.ac-intro-right {
  /* Takes the accordion list */
}

@media (max-width: 1023px) {
  .ac-intro-left {
    text-align: center;
  }
  .ac-intro-left .ac-intro-title,
  .ac-intro-left .ac-intro-desc {
    text-align: center;
  }
  .ac-intro-trust {
    align-items: center;
  }
}

/* ===== Zig-Zag Feature Layout ===== */
.ac-zigzag-features {
  display: flex;
  flex-direction: column;
  gap: 5rem;
}

.ac-zigzag-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2.5rem;
  align-items: center;
}

@media (min-width: 768px) {
  .ac-zigzag-row {
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
  }

  .ac-zigzag-row.ac-zigzag-reverse {
    direction: rtl;
  }

  .ac-zigzag-row.ac-zigzag-reverse > * {
    direction: ltr;
  }
}

/* Visual side with icons */
.ac-zigzag-visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

/* Glass Card Container - "Showcase Window" Effect */
.ac-zigzag-icon-wrapper {
  display: flex;
  gap: 1.5rem;
  padding: 3rem 4rem;
  border-radius: 28px;
  min-width: 280px;
  min-height: 200px;
  align-items: center;
  justify-content: center;
  /* Glass card background */
  background: linear-gradient(145deg,
    rgba(255, 255, 255, 0.04) 0%,
    rgba(212, 175, 55, 0.06) 50%,
    rgba(0, 0, 0, 0.2) 100%
  );
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  /* Gold border */
  border: 1px solid rgba(212, 175, 55, 0.25);
  /* Layered shadows for depth */
  box-shadow:
    0 20px 60px rgba(0, 0, 0, 0.3),
    0 8px 24px rgba(0, 0, 0, 0.2),
    0 0 80px rgba(212, 175, 55, 0.08),
    inset 0 1px 0 rgba(255, 255, 255, 0.06),
    inset 0 0 40px rgba(212, 175, 55, 0.03);
  /* Concentric circle glow behind */
  position: relative;
  overflow: visible;
  transition: all 0.4s ease;
}

/* Ambient glow ring behind the card */
.ac-zigzag-icon-wrapper::before {
  content: '';
  position: absolute;
  inset: -40px;
  border-radius: 50%;
  background: radial-gradient(
    circle at 50% 50%,
    rgba(212, 175, 55, 0.12) 0%,
    rgba(212, 175, 55, 0.06) 30%,
    rgba(212, 175, 55, 0.02) 50%,
    transparent 70%
  );
  z-index: -1;
  pointer-events: none;
}

/* Subtle orbital ring */
.ac-zigzag-icon-wrapper::after {
  content: '';
  position: absolute;
  inset: -60px;
  border-radius: 50%;
  border: 1px dashed rgba(212, 175, 55, 0.1);
  z-index: -2;
  pointer-events: none;
  animation: ac-orbital-spin 30s linear infinite;
}

@keyframes ac-orbital-spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.ac-zigzag-row:hover .ac-zigzag-icon-wrapper {
  border-color: rgba(212, 175, 55, 0.45);
  box-shadow:
    0 25px 70px rgba(0, 0, 0, 0.35),
    0 10px 30px rgba(0, 0, 0, 0.25),
    0 0 100px rgba(212, 175, 55, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    inset 0 0 50px rgba(212, 175, 55, 0.05);
}

.ac-zigzag-icon {
  width: 100px;
  height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 24px;
  background: linear-gradient(145deg,
    rgba(212, 175, 55, 0.12) 0%,
    rgba(212, 175, 55, 0.04) 100%
  );
  border: 1.5px solid rgba(212, 175, 55, 0.4);
  box-shadow:
    0 8px 32px rgba(0, 0, 0, 0.15),
    0 0 20px rgba(212, 175, 55, 0.1);
  transition: all 0.4s ease;
}

.ac-zigzag-icon .material-symbols-outlined {
  font-size: 48px;
  font-variation-settings: 'wght' 300, 'GRAD' 0;
  background: linear-gradient(180deg,
    #FFFAF0 0%,
    #FFD700 40%,
    #D4AF37 70%,
    #B8860B 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 3px 6px rgba(212, 175, 55, 0.35));
}

.ac-zigzag-icon-secondary {
  width: 80px;
  height: 80px;
  opacity: 0.7;
  transform: translateY(20px);
}

.ac-zigzag-icon-secondary .material-symbols-outlined {
  font-size: 38px;
}

.ac-zigzag-row:hover .ac-zigzag-icon {
  border-color: rgba(212, 175, 55, 0.6);
  box-shadow:
    0 12px 40px rgba(0, 0, 0, 0.2),
    0 0 30px rgba(212, 175, 55, 0.2);
  transform: translateY(-4px);
}

/* Content side */
.ac-zigzag-content {
  padding: 1rem 0;
}

.ac-zigzag-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--ac-text-primary);
  margin-bottom: 1rem;
  line-height: 1.3;
}

.ac-zigzag-desc {
  font-size: 1rem;
  color: var(--ac-text-secondary);
  line-height: 1.7;
  margin-bottom: 1.25rem;
}

.ac-zigzag-points {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.ac-zigzag-points li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.95rem;
  color: var(--ac-text-secondary);
}

.ac-zigzag-points .material-symbols-outlined {
  font-size: 20px;
  background: linear-gradient(180deg, #FFD700 0%, #D4AF37 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  filter: drop-shadow(0 0 4px rgba(212, 175, 55, 0.4));
}

/* ===== Increased Section Spacing ===== */
.ac-steps-section {
  padding: 7rem 0;
}

.ac-intro-section {
  padding: 7rem 0;
}

.ac-features-section {
  padding: 7rem 0;
}

.ac-table-section {
  padding: 7rem 0;
}

.ac-usecase-section {
  padding: 7rem 0;
}

.ac-bitrate-section {
  padding: 5rem 0;
}

.ac-faq-section {
  padding: 7rem 0;
}

.ac-tools-section {
  padding: 7rem 0;
}

/* ===== Responsive Utilities ===== */
@media (max-width: 640px) {
  .ac-upload-area {
    min-height: 320px;
    padding: 2rem 1.5rem;
  }

  .ac-upload-icon-wrapper {
    width: 100px;
    height: 100px;
  }

  .ac-upload-icon-ring .material-symbols-outlined {
    font-size: 44px;
  }

  .ac-section-title {
    font-size: 1.75rem;
  }

  .ac-zigzag-icon-wrapper {
    flex-direction: column;
    gap: 1rem;
  }

  .ac-zigzag-icon {
    width: 80px;
    height: 80px;
  }

  .ac-zigzag-icon .material-symbols-outlined {
    font-size: 36px;
  }

  .ac-zigzag-icon-secondary {
    width: 64px;
    height: 64px;
    transform: translateY(0);
  }

  .ac-zigzag-title {
    font-size: 1.25rem;
  }

  /* Reduce section spacing on mobile */
  .ac-steps-section,
  .ac-intro-section,
  .ac-features-section,
  .ac-table-section,
  .ac-usecase-section,
  .ac-faq-section,
  .ac-tools-section {
    padding: 4rem 0;
  }
}