/* Apple UI Style Landing Page CSS */
/* Design System - CSS Custom Properties */
:root {
  /* Colors - Neutral Base + Single Accent */
  --color-primary: #2563EB;
  --color-primary-dark: #1D4ED8;
  --color-secondary: #2563EB;
  --color-background: #F6F7FB;
  --color-background-secondary: #F8FAFC;
  --color-surface: #FFFFFF;
  --color-text-primary: #0F172A;
  --color-text-secondary: #64748B;
  --color-text-tertiary: #94A3B8;
  --color-border: #E8EEF6;
  --color-shadow: rgba(15, 23, 42, 0.06);
  --color-overlay: rgba(15, 23, 42, 0.35);
  --color-icon-surface: #F1F5FF;

  /* Typography */
  --font-family-primary: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;
  --font-size-6xl: 3.75rem;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;
  --spacing-5xl: 8rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

  /* Transitions */
  --transition-fast: 0.15s ease-out;
  --transition-base: 0.3s ease-out;
  --transition-slow: 0.5s ease-out;
}

/* Reset and Base Styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-background);
  overflow-x: hidden;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 {
  font-size: var(--font-size-5xl);
  font-weight: 700;
}

h2 {
  font-size: var(--font-size-4xl);
}

h3 {
  font-size: var(--font-size-3xl);
}

p {
  margin-bottom: var(--spacing-md);
  color: var(--color-text-secondary);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary-dark);
}

/* Layout Components */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.section {
  padding: var(--spacing-4xl) 0;
}

.section--hero {
  padding: var(--spacing-5xl) 0;
  background: var(--color-background);
}

.section--features {
  background-color: var(--color-background-secondary);
}

.section--tone-a {
  background: #f5f6f8;
}

.section--tone-b {
  background: #eceff3;
}

.section--tone-c {
  background: #1f2328;
  color: #f5f6f8;
}

.section--tone-c .features__title,
.section--tone-c .workflow__title,
.section--tone-c .pricing__title,
.section--tone-c .resources__title,
.section--tone-c .faq__title,
.section--tone-c .social-proof__title {
  color: #f5f6f8;
}

.section--tone-c .feature-card,
.section--tone-c .plan-card,
.section--tone-c .resource-card,
.section--tone-c .faq-card,
.section--tone-c .stat-card {
  background: rgba(255, 255, 255, 0.06);
  box-shadow: none;
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.section--tone-c .feature-card__description,
.section--tone-c .workflow__step-description,
.section--tone-c .pricing__subtitle,
.section--tone-c .resources__subtitle,
.section--tone-c .faq__subtitle,
.section--tone-c .stat-card__label,
.section--tone-c .resource-card__desc,
.section--tone-c .faq-card__answer {
  color: rgba(245, 246, 248, 0.75);
}

/* Header Navigation */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  transition: all var(--transition-base);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-md) 0;
}

.nav__logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-primary);
  text-decoration: none;
}

.nav__menu {
  display: flex;
  list-style: none;
  gap: var(--spacing-xl);
}

.nav__link {
  color: var(--color-text-primary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav__link:hover {
  color: var(--color-primary);
}

.nav__cta {
  display: flex;
  gap: var(--spacing-md);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-sm) var(--spacing-lg);
  border: none;
  border-radius: var(--radius-full);
  font-family: inherit;
  font-size: var(--font-size-sm);
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn--primary {
  background: var(--color-primary);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn--primary:hover {
  background: linear-gradient(180deg, var(--color-primary), var(--color-primary-dark));
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
  color: white;
}

.btn--secondary {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn--secondary:hover {
  background: var(--color-primary);
  color: white;
}

.btn--large {
  padding: var(--spacing-md) var(--spacing-2xl);
  font-size: var(--font-size-base);
}

.btn--small {
  padding: var(--spacing-xs) var(--spacing-md);
  font-size: var(--font-size-xs);
}

/* Hero Section */
.hero {
  text-align: center;
  padding-top: 50px;
}

.hero__title {
  font-size: var(--font-size-6xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-lg);
  line-height: 1.1;
}

.hero__subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-2xl);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero__cta {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: var(--spacing-4xl);
}

.hero__trial {
  max-width: 800px;
  margin: 0 auto;
}

/* Trial Upload Component */
.trial-upload {
  background: var(--color-surface);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
  margin-top: var(--spacing-2xl);
}

.trial-upload__header {
  padding: var(--spacing-2xl) var(--spacing-2xl) var(--spacing-lg);
  text-align: center;
  background: var(--color-background-secondary);
}

.trial-upload__title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.trial-upload__subtitle {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

.trial-upload__limits {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
}

.limit-badge {
  background: #F1F5F9;
  color: #334155;
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 600;
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.limit-badge--premium {
  background: #EAF0FF;
  color: #1D4ED8;
  border-color: rgba(37, 99, 235, 0.35);
}

/* Dropzone Styles */
.trial-upload__dropzone {
  padding: var(--spacing-2xl);
  min-height: 300px;
  position: relative;
}

.dropzone-content {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--spacing-3xl) var(--spacing-2xl);
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-base);
  background: var(--color-background-secondary);
}

.dropzone-content:hover,
.dropzone-content.dragover {
  border-color: var(--color-primary);
  background: rgba(37, 99, 235, 0.05);
  transform: translateY(-2px);
}

.dropzone-icon {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
  transition: color var(--transition-base);
}

.dropzone-content:hover .dropzone-icon,
.dropzone-content.dragover .dropzone-icon {
  color: var(--color-primary);
}

.dropzone-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.dropzone-subtitle {
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-lg);
}

.dropzone-specs {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
}

.dropzone-specs span {
  background: var(--color-surface);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--radius-md);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

/* Upload Progress */
.upload-progress {
  text-align: center;
  padding: var(--spacing-3xl) var(--spacing-2xl);
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--color-background-secondary);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--spacing-lg);
}

.progress-fill {
  height: 100%;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-base);
  width: 0%;
}

.progress-text {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-text-primary);
  margin: 0;
}

/* Translation Result */
.translation-result {
  padding: var(--spacing-2xl);
  background: rgba(34, 197, 94, 0.05);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(34, 197, 94, 0.2);
}

.result-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.result-header h4 {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: #059669;
  margin: 0;
}

.result-actions {
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.result-stats {
  display: flex;
  gap: var(--spacing-xl);
  justify-content: center;
  flex-wrap: wrap;
}

.stat-item {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.stat-item strong {
  color: var(--color-text-primary);
  font-weight: 600;
}

/* Trial Footer */
.trial-upload__footer {
  padding: var(--spacing-lg) var(--spacing-2xl);
  background: var(--color-background-secondary);
  text-align: center;
}

.trial-note {
  margin: 0;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.trial-remaining {
  font-weight: 600;
  color: var(--color-text-primary);
}

.trial-upgrade {
  color: var(--color-primary);
  font-weight: 600;
  margin-left: var(--spacing-md);
  transition: color var(--transition-fast);
}

.trial-upgrade:hover {
  color: var(--color-primary-dark);
}

/* Trial Translate Module */
.hero__translate {
  max-width: 900px;
  margin: var(--spacing-3xl) auto 0;
}

.trial-translate {
  background: var(--color-surface);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-lg);
  border: 1px solid rgba(0, 0, 0, 0.04);
  overflow: hidden;
}

.trial-translate__header {
  padding: var(--spacing-2xl);
  text-align: center;
  background: var(--color-background-secondary);
}

.trial-translate__title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.trial-translate__subtitle {
  color: var(--color-text-secondary);
  margin: 0;
}

.trial-translate__body {
  padding: var(--spacing-2xl);
  display: grid;
  gap: var(--spacing-xl);
}

.trial-translate__input {
  display: grid;
  gap: var(--spacing-md);
}

.trial-translate__label {
  font-weight: 600;
  color: var(--color-text-primary);
}

.trial-translate__textarea {
  width: 100%;
  min-height: 160px;
  padding: var(--spacing-md);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  background: #fff;
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  resize: vertical;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.trial-translate__textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
  outline: none;
}

.trial-translate__selectors {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--spacing-md);
}

.trial-select label {
  display: block;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}

.trial-select__control {
  width: 100%;
  padding: var(--spacing-sm) var(--spacing-md);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-background);
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.trial-select__control:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
  outline: none;
}

.trial-translate__actions {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
  flex-wrap: wrap;
}

.trial-translate__status {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

.trial-translate__status.is-success {
  color: #059669;
}

.trial-translate__status.is-error {
  color: #dc2626;
}

.trial-translate__status.is-muted {
  color: var(--color-text-tertiary);
}

.trial-translate__output {
  background: var(--color-background-secondary);
  border-radius: var(--radius-lg);
  border: 1px dashed var(--color-border);
  padding: var(--spacing-lg);
  min-height: 140px;
}

.trial-translate__output-title {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-sm);
}

.trial-translate__result {
  white-space: pre-wrap;
  color: var(--color-text-primary);
}

.trial-translate__result.is-empty {
  color: var(--color-text-tertiary);
}

/* Features Section */
.features {
  text-align: center;
}

.features__title {
  margin-bottom: var(--spacing-3xl);
}

.features__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-2xl);
  margin-top: var(--spacing-3xl);
}

.feature-card {
  background: var(--color-surface);
  padding: 32px;
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.06);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
}

.feature-card__icon {
  width: 48px;
  height: 48px;
  margin: 0 auto var(--spacing-lg);
  background: var(--color-icon-surface);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
}

.feature-card__icon-svg {
  width: 24px;
  height: 24px;
}

.feature-card__title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: 8px;
}

.feature-card__description {
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.feature-card__highlight {
  display: flex;
  gap: var(--spacing-sm);
  justify-content: center;
  flex-wrap: wrap;
}

.highlight-badge {
  background: #F1F5F9;
  color: #334155;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-md);
  font-size: var(--font-size-xs);
  font-weight: 600;
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.highlight-badge--premium {
  background: #EAF0FF;
  color: #1D4ED8;
  border-color: rgba(37, 99, 235, 0.35);
}

/* Workflow Section */
.workflow {
  text-align: center;
}

.workflow__title {
  margin-bottom: var(--spacing-3xl);
}

.workflow__steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--spacing-xl);
  margin-top: var(--spacing-3xl);
  position: relative;
}

.workflow__step {
  position: relative;
  padding: var(--spacing-lg);
}

.workflow__step-number {
  width: 50px;
  height: 50px;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: var(--font-size-lg);
  margin: 0 auto var(--spacing-lg);
}

.workflow__step-title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.workflow__step-description {
  color: var(--color-text-secondary);
}

/* Social Proof */
.social-proof {
  text-align: center;
}

.social-proof__title {
  margin-bottom: var(--spacing-md);
}

.social-proof__subtitle {
  color: var(--color-text-secondary);
  max-width: 680px;
  margin: 0 auto var(--spacing-2xl);
}

.social-proof__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--spacing-xl);
}

.stat-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-align: left;
  box-shadow: var(--shadow-sm);
}

.stat-card__value {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
}

.stat-card__label {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

/* Pricing Section */
.pricing {
  text-align: center;
}

.pricing__title {
  margin-bottom: var(--spacing-md);
}

.pricing__subtitle {
  color: var(--color-text-secondary);
  max-width: 720px;
  margin: 0 auto var(--spacing-3xl);
}

.pricing__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--spacing-2xl);
  align-items: stretch;
  /* 为向上突出的 STARTUP 卡片及其徽章预留空间 */
  padding-top: 34px;
}

.plan-card {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  box-shadow: var(--shadow-md);
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.plan-card--free {
  border: 1px solid rgba(37, 99, 235, 0.2);
}

.plan-card__name {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-sm);
}

.plan-card__price {
  display: flex;
  align-items: baseline;
  gap: var(--spacing-xs);
  font-weight: 700;
}

.plan-card__currency {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.plan-card__amount {
  font-size: var(--font-size-2xl);
  color: var(--color-text-surface);
}

.plan-card__period {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.plan-card__meta {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.plan-card__features {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: var(--spacing-sm);
}

.plan-card__feature {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-sm);
}

.plan-card__feature.is-off {
  color: var(--color-text-secondary);
}

.plan-card__check {
  width: 20px;
  text-align: center;
}

.plan-card__actions {
  margin-top: auto;
}

.btn--block {
  display: inline-flex;
  width: 100%;
  justify-content: center;
}

/* STARTUP 主推卡片 - 向上突出 + 品牌色高亮（适配深色 tone-c 背景） */
/* 注意：需用 .plan-card.plan-card--startup 双类选择器，压过 .section--tone-c .plan-card 的覆盖 */
.plan-card.plan-card--startup {
  position: relative;
  border: 1.5px solid #3b82f6;
  background: linear-gradient(180deg, rgba(59, 130, 246, 0.18) 0%, rgba(124, 58, 237, 0.12) 100%);
  box-shadow: 0 18px 44px -10px rgba(59, 130, 246, 0.45);
  transform: translateY(-16px);
  z-index: 2;
}

.plan-card--startup .plan-card__name {
  color: #93c5fd;
}

.plan-card--startup .plan-card__amount {
  font-size: var(--font-size-4xl);
  color: #60a5fa;
  background: linear-gradient(135deg, #60a5fa 0%, #a78bfa 55%, #f0abfc 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* STARTUP 顶部徽章 */
.plan-card__badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 3;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 5px 16px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, #fbbf24 0%, #f97316 100%);
  color: #1f2328;
  font-size: var(--font-size-sm);
  font-weight: 800;
  letter-spacing: 0.02em;
  white-space: nowrap;
  box-shadow: 0 6px 18px -4px rgba(249, 115, 22, 0.55);
}

/* STARTUP CTA 按钮 - 蓝紫渐变 + 呼吸光效 */
.plan-card--startup .plan-card__actions .btn {
  background: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  border: none;
  color: #ffffff;
  animation: startup-btn-glow 2.6s ease-in-out infinite;
}

.plan-card--startup .plan-card__actions .btn:hover {
  transform: translateY(-2px);
  filter: brightness(1.08);
}

@keyframes startup-btn-glow {
  0%,
  100% {
    box-shadow: 0 8px 22px -6px rgba(59, 130, 246, 0.55);
  }

  50% {
    box-shadow: 0 10px 30px -4px rgba(139, 92, 246, 0.75);
  }
}

/* FREE 套餐折叠区 */
.pricing__free-disclosure {
  margin-top: var(--spacing-xl);
  text-align: center;
}

.pricing__free-summary {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  list-style: none;
  appearance: none;
  -webkit-appearance: none;
  color: #93c5fd;
  font-weight: 600;
  padding: 10px 22px;
  border: 1.5px dashed rgba(147, 197, 253, 0.55);
  border-radius: var(--radius-full);
  transition: background var(--transition-base), border-color var(--transition-base);
  user-select: none;
}

.pricing__free-summary:hover {
  background: rgba(59, 130, 246, 0.12);
  border-color: #93c5fd;
}

.pricing__free-summary::-webkit-details-marker {
  display: none;
}

.pricing__free-toggle {
  font-size: var(--font-size-sm);
  transition: transform var(--transition-base);
}

.pricing__free-disclosure[open] .pricing__free-toggle {
  transform: rotate(180deg);
}

.pricing__free-body {
  margin-top: var(--spacing-xl);
  display: flex;
  justify-content: center;
}

.pricing__free-body .plan-card {
  width: 100%;
  max-width: 440px;
  text-align: left;
  background: rgba(255, 255, 255, 0.08);
}

.pricing__free-body .plan-card--free {
  border: 1px solid rgba(147, 197, 253, 0.35);
}

/* Resources Section */
.resources {
  text-align: center;
}

.resources__title {
  margin-bottom: var(--spacing-md);
}

.resources__subtitle {
  color: var(--color-text-secondary);
  max-width: 720px;
  margin: 0 auto var(--spacing-3xl);
}

.resources__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--spacing-xl);
}

.resource-card {
  background: var(--color-surface);
  padding: var(--spacing-xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  text-align: left;
}

.resource-card__title {
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-sm);
}

.resource-card__desc {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

/* FAQ Section */
.faq {
  text-align: center;
}

.faq__title {
  margin-bottom: var(--spacing-md);
}

.faq__subtitle {
  color: var(--color-text-secondary);
  max-width: 680px;
  margin: 0 auto var(--spacing-3xl);
}

.faq__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--spacing-xl);
}

.faq-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: var(--spacing-xl);
  text-align: left;
  box-shadow: var(--shadow-sm);
}

.faq-card__question {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-sm);
}

.faq-card__answer {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  line-height: 1.6;
}

/* CTA Section */
.cta-section {
  background: var(--color-background-secondary);
  color: var(--color-text-primary);
  text-align: center;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
}

.cta-section__title {
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-lg);
}

.cta-section__description {
  color: var(--color-text-secondary);
  font-size: var(--font-size-lg);
  margin-bottom: var(--spacing-2xl);
}

.cta-section__actions {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
}

.cta-section .btn--secondary {
  background: transparent;
  color: var(--color-primary);
  border: 1px solid rgba(37, 99, 235, 0.35);
}

.cta-section .btn--secondary:hover {
  background: rgba(37, 99, 235, 0.08);
  color: var(--color-primary-dark);
}

/* Footer */
.footer {
  background-color: var(--color-text-primary);
  color: var(--color-text-tertiary);
  text-align: center;
  padding: var(--spacing-2xl) 0;
}

.footer__content {
  font-size: var(--font-size-sm);
}

.footer__link {
  color: var(--color-text-tertiary);
  transition: color var(--transition-fast);
}

.footer__link:hover {
  color: white;
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav__menu {
    display: none;
  }

  .hero__title {
    font-size: var(--font-size-4xl);
  }

  .hero__subtitle {
    font-size: var(--font-size-lg);
  }

  .hero__cta {
    flex-direction: column;
    align-items: center;
  }

  .trial-upload__header {
    padding: var(--spacing-lg);
  }

  .trial-upload__dropzone {
    padding: var(--spacing-lg);
  }

  .dropzone-content {
    padding: var(--spacing-2xl) var(--spacing-lg);
  }

  .trial-upload__limits {
    flex-direction: column;
    align-items: center;
  }

  .trial-translate__selectors {
    grid-template-columns: 1fr;
  }

  .trial-translate__actions {
    flex-direction: column;
    align-items: stretch;
  }

  .result-header {
    flex-direction: column;
    text-align: center;
  }

  .result-stats {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .cta-section__actions {
    flex-direction: column;
    align-items: center;
  }

  .features__grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .workflow__steps {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }

  .container {
    padding: 0 var(--spacing-md);
  }

  .section {
    padding: var(--spacing-2xl) 0;
  }

  .section--hero {
    padding: var(--spacing-3xl) 0;
  }
}

@media (max-width: 480px) {
  .hero__title {
    font-size: var(--font-size-3xl);
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  .feature-card {
    padding: 32px;
  }

  .trial-upload__title {
    font-size: var(--font-size-xl);
  }

  .dropzone-specs {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {

  0%,
  100% {
    opacity: 1;
  }

  50% {
    opacity: 0.5;
  }
}

.animate-fade-in-up {
  animation: fadeInUp 0.6s ease-out;
}

.animate-pulse {
  animation: pulse 2s infinite;
}

/* Utility Classes */
.text-center {
  text-align: center;
}

.text-left {
  text-align: left;
}

.text-right {
  text-align: right;
}

.mb-0 {
  margin-bottom: 0;
}

.mt-lg {
  margin-top: var(--spacing-lg);
}

.hidden {
  display: none;
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
  :root {
    --color-background: #000000;
    --color-background-secondary: #1C1C1E;
    --color-surface: #2C2C2E;
    --color-text-primary: #FFFFFF;
    --color-text-secondary: #98989D;
    --color-text-tertiary: #636366;
    --color-border: #38383A;
  }

  .header {
    background: rgba(0, 0, 0, 0.8);
  }

  .section--hero {
    background: var(--color-background);
  }

  .trial-upload__header {
    background: var(--color-background-secondary);
  }

  .dropzone-content {
    background: var(--color-background-secondary);
    border-color: var(--color-border);
  }

  .translation-result {
    background: rgba(34, 197, 94, 0.1);
    border-color: rgba(34, 197, 94, 0.3);
  }
}

/* 预览模态框样式 */
.preview-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
}

.preview-modal__overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
}

.preview-modal__content {
  position: relative;
  background: var(--color-background);
  border-radius: 16px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
  max-width: 800px;
  width: 90%;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.preview-modal__header {
  padding: 24px 24px 16px;
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.preview-modal__header h3 {
  margin: 0;
  font-size: var(--font-size-xl);
  font-weight: 600;
  color: var(--color-text-primary);
}

.preview-modal__close {
  background: none;
  border: none;
  font-size: 24px;
  color: var(--color-text-secondary);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  transition: all 0.2s ease;
}

.preview-modal__close:hover {
  background: var(--color-background-secondary);
  color: var(--color-text-primary);
}

.preview-modal__info {
  padding: 16px 24px;
  background: var(--color-background-secondary);
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
}

.preview-modal__info span {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.preview-modal__body {
  flex: 1;
  overflow-y: auto;
  padding: 16px 24px;
}

.preview-item {
  display: flex;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.preview-item:last-child {
  border-bottom: none;
}

.preview-item__index {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.preview-item__content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.preview-item__source,
.preview-item__target {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.preview-item__source label,
.preview-item__target label {
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.preview-text {
  padding: 12px;
  background: var(--color-background-secondary);
  border-radius: 8px;
  font-size: var(--font-size-sm);
  line-height: 1.5;
  color: var(--color-text-primary);
  word-break: break-word;
}

.preview-empty {
  text-align: center;
  padding: 48px 24px;
  color: var(--color-text-secondary);
  font-size: var(--font-size-base);
}

.preview-modal__footer {
  padding: 16px 24px;
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: flex-end;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .preview-modal__content {
    width: 95%;
    max-height: 90vh;
  }

  .preview-modal__header,
  .preview-modal__info,
  .preview-modal__body,
  .preview-modal__footer {
    padding-left: 16px;
    padding-right: 16px;
  }

  .preview-modal__info {
    flex-direction: column;
    gap: 8px;
  }

  .preview-item {
    flex-direction: column;
    gap: 12px;
  }

  .preview-item__index {
    align-self: flex-start;
  }
}

/* Language Switcher */
.lang-switcher {
  position: relative;
  margin-left: var(--spacing-md);
}

.lang-switcher__toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.05);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lang-switcher__toggle:hover {
  background: var(--color-primary);
  color: white;
}

.lang-switcher__menu {
  position: absolute;
  top: 100%;
  right: 0;
  margin-top: var(--spacing-sm);
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-border);
  min-width: 120px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--transition-fast);
  z-index: 1000;
}

.lang-switcher:hover .lang-switcher__menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.lang-switcher__item {
  display: block;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  font-weight: 500;
  transition: background var(--transition-fast);
}

.lang-switcher__item:first-child {
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.lang-switcher__item:last-child {
  border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

.lang-switcher__item:hover {
  background: var(--color-background-secondary);
  color: var(--color-primary);
}

.lang-switcher__item.is-active {
  color: var(--color-primary);
  background: rgba(37, 99, 235, 0.08);
}