:root {
  /* Logo配色提取 */
  --sky-blue: #4A9FD4;
  --sky-blue-light: #7BBCE8;
  --sky-blue-dark: #2E7CB0;
  --deep-blue: #2E5C8A;
  --warm-orange: #E8843C;
  --warm-orange-light: #F0A668;
  --golden: #F5C842;
  --golden-light: #F9E08C;
  --cream: #FDF8F0;
  --cream-dark: #F5EDE0;
  --warm-white: #FFFBF5;
  --text-primary: #2C3E50;
  --text-secondary: #5A6C7D;
  --text-tertiary: #8FA1B3;
  --bg-primary: #FFFBF5;
  --bg-secondary: #F5EDE0;
  --bg-card: #FFFFFF;
  --bg-card-hover: #FFF8EE;
  --border-subtle: rgba(74, 159, 212, 0.12);
  --border-light: rgba(74, 159, 212, 0.25);
  --accent: #4A9FD4;
  --accent-hover: #2E7CB0;
  --accent-light: rgba(74, 159, 212, 0.1);
  --accent-glow: rgba(74, 159, 212, 0.2);
  --font-display: "Noto Sans SC", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: "Noto Sans SC", -apple-system, BlinkMacSystemFont, sans-serif;
  --max-width: 1200px;
  --section-padding: clamp(64px, 10vw, 120px);
  --container-padding: clamp(20px, 5vw, 48px);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.section-header {
  margin-bottom: 56px;
}

.section-header.center {
  text-align: center;
}

.section-header.center .section-lead {
  margin-left: auto;
  margin-right: auto;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--sky-blue);
  margin-bottom: 16px;
  font-family: var(--font-body);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.section-lead {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 600px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: 16px;
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  border: none;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--sky-blue-dark) 100%);
  color: #fff;
  box-shadow: 0 4px 16px rgba(74, 159, 212, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--sky-blue-dark) 0%, var(--deep-blue) 100%);
  box-shadow: 0 8px 24px rgba(74, 159, 212, 0.4);
  transform: translateY(-2px);
}

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

.btn-ghost:hover {
  background: var(--accent-light);
  color: var(--sky-blue-dark);
  border-color: var(--sky-blue);
  transform: translateY(-2px);
}

.btn-large {
  padding: 18px 36px;
  font-size: 1.05rem;
}

.btn:disabled, .btn[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 251, 245, 0.92);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border-subtle);
}

.nav .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none !important;
}

.nav-logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
}

.nav-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
  font-family: var(--font-display);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 1px;
  transition: all 0.3s ease;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  padding: 8px 16px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 10px;
  transition: all 0.2s ease;
  text-decoration: none !important;
  position: relative;
}

.nav-link:hover {
  color: var(--sky-blue-dark);
  background: var(--accent-light);
}

main {
  padding-top: 72px;
}

/* Hero Section */
.hero-section {
  min-height: calc(100vh - 72px);
  display: flex;
  align-items: center;
  padding: var(--section-padding) 0;
  position: relative;
  overflow: hidden;
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg-glow {
  position: absolute;
  top: -10%;
  right: -5%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(74, 159, 212, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

.hero-bg-grid {
  position: absolute;
  inset: 0;
  background-image: 
    radial-gradient(circle at 20% 80%, rgba(245, 200, 66, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(74, 159, 212, 0.06) 0%, transparent 50%);
  pointer-events: none;
}

.hero-section .container {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-content {
  max-width: 560px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 20px;
  background: rgba(74, 159, 212, 0.1);
  border: 1px solid rgba(74, 159, 212, 0.2);
  border-radius: 100px;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--sky-blue-dark);
  margin-bottom: 28px;
}

.eyebrow-dot {
  width: 8px;
  height: 8px;
  background: var(--warm-orange);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.3); }
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 4.5rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 16px;
}

.title-line {
  display: block;
}

.title-line-accent {
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--deep-blue) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 500;
  color: var(--text-secondary);
  letter-spacing: 0.02em;
  margin-bottom: 20px;
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.15rem);
  color: var(--text-tertiary);
  line-height: 1.8;
  margin-bottom: 36px;
}

.hero-cta {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* Hero Logo */
.hero-logo {
  width: 100%;
  max-width: 400px;
  margin: 0 auto;
  animation: float 6s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.hero-logo img {
  width: 100%;
  height: auto;
  border-radius: 24px;
  box-shadow: 0 20px 60px rgba(74, 159, 212, 0.2);
}

/* Sections */
section {
  padding: var(--section-padding) 0;
  position: relative;
}

section:nth-child(even) {
  background: var(--bg-secondary);
}

/* Philosophy */
.philosophy-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 56px;
}

.philosophy-item {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 24px;
  padding: 36px 28px;
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.philosophy-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--sky-blue) 0%, var(--golden) 100%);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.philosophy-item:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
  transform: translateY(-4px);
  box-shadow: 0 16px 40px rgba(74, 159, 212, 0.12);
}

.philosophy-item:hover::before {
  opacity: 1;
}

.philosophy-num {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--sky-blue);
  margin-bottom: 20px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.1em;
}

.philosophy-item h3 {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
  color: var(--text-primary);
  line-height: 1.4;
}

.philosophy-item p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.philosophy-quote {
  margin-top: 64px;
  text-align: center;
  padding: 48px 32px;
  background: linear-gradient(135deg, rgba(74, 159, 212, 0.08) 0%, rgba(245, 200, 66, 0.06) 100%);
  border-radius: 24px;
  border: 1px solid rgba(74, 159, 212, 0.1);
}

.quote-icon {
  width: 40px;
  height: 40px;
  color: var(--sky-blue);
  margin: 0 auto 20px;
  opacity: 0.5;
}

.philosophy-quote p {
  font-family: var(--font-display);
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: 0.02em;
  line-height: 1.6;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  margin-top: 48px;
  align-items: start;
}

.about-main {
  max-width: 480px;
}

.about-lead {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.7;
  margin-bottom: 16px;
}

.about-main p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.about-cards {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.about-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  padding: 32px;
  transition: all 0.3s ease;
}

.about-card:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
  box-shadow: 0 12px 32px rgba(74, 159, 212, 0.1);
}

.card-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, rgba(74, 159, 212, 0.1) 0%, rgba(245, 200, 66, 0.1) 100%);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--sky-blue);
}

.card-icon svg {
  width: 24px;
  height: 24px;
}

.about-card h3 {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.about-card p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Steps */
.steps {
  margin-top: 56px;
  max-width: 700px;
}

.step {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 28px;
  margin-bottom: 40px;
  position: relative;
}

.step:last-child {
  margin-bottom: 0;
}

.step-marker {
  display: flex;
  flex-direction: column;
  align-items: center;
  position: relative;
}

.step-num {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--sky-blue-dark) 100%);
  border-radius: 50%;
  font-size: 1.125rem;
  font-weight: 700;
  color: #fff;
  position: relative;
  z-index: 1;
  box-shadow: 0 4px 16px rgba(74, 159, 212, 0.3);
}

.step-line {
  width: 3px;
  flex: 1;
  min-height: 40px;
  background: linear-gradient(180deg, var(--sky-blue) 0%, transparent 100%);
  margin-top: 8px;
  opacity: 0.3;
}

.step-content h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.step-content p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.test-note {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 64px;
  padding-top: 48px;
  border-top: 1px solid var(--border-subtle);
}

.test-note-item {
  padding: 28px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  transition: all 0.3s ease;
}

.test-note-item:hover {
  border-color: var(--border-light);
  box-shadow: 0 8px 24px rgba(74, 159, 212, 0.08);
}

.note-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, rgba(74, 159, 212, 0.1) 0%, rgba(245, 200, 66, 0.1) 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
  color: var(--sky-blue);
}

.note-icon svg {
  width: 20px;
  height: 20px;
}

.test-note-item strong {
  display: block;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  font-family: var(--font-display);
}

.test-note-item p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* Download */
.download-box {
  margin-top: 48px;
  padding: 48px;
  background: linear-gradient(135deg, var(--bg-card) 0%, rgba(74, 159, 212, 0.05) 100%);
  border: 2px solid var(--border-light);
  border-radius: 28px;
  text-align: center;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.download-logo {
  width: 80px;
  height: 80px;
  margin: 0 auto 24px;
  border-radius: 20px;
  box-shadow: 0 8px 24px rgba(74, 159, 212, 0.2);
}

.download-logo img {
  width: 100%;
  height: 100%;
  border-radius: 20px;
}

.download-info h3 {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.download-version {
  font-size: 0.9375rem;
  color: var(--text-tertiary);
  margin-bottom: 8px;
}

.download-version strong {
  color: var(--sky-blue);
}

.download-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 28px;
}

.download-reminder {
  margin-top: 32px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
  padding: 20px 24px;
  background: rgba(245, 200, 66, 0.08);
  border: 1px solid rgba(245, 200, 66, 0.2);
  border-radius: 16px;
}

.reminder-icon {
  width: 24px;
  height: 24px;
  color: var(--golden);
  flex-shrink: 0;
  margin-top: 2px;
}

.download-reminder p {
  font-size: 0.875rem;
  color: var(--text-tertiary);
  line-height: 1.6;
}

/* Feedback */
.feedback-hint {
  margin-top: 24px;
  padding: 20px 24px;
  background: rgba(74, 159, 212, 0.06);
  border: 1px solid rgba(74, 159, 212, 0.15);
  border-radius: 16px;
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.hint-icon {
  width: 24px;
  height: 24px;
  color: var(--sky-blue);
  flex-shrink: 0;
  margin-top: 2px;
}

.feedback-hint p {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.feedback-hint strong {
  color: var(--sky-blue-dark);
}

.feedback-mode {
  margin-top: 24px;
  padding: 16px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 12px;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.feedback-form {
  margin-top: 40px;
  max-width: 800px;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-bottom: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 20px;
}

.form-group:last-child {
  margin-bottom: 0;
}

.form-group label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 14px 16px;
  background: var(--bg-card);
  border: 2px solid var(--border-subtle);
  border-radius: 14px;
  font-size: 1rem;
  font-family: inherit;
  color: var(--text-primary);
  transition: all 0.2s ease;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--text-tertiary);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--sky-blue);
  box-shadow: 0 0 0 4px var(--accent-light);
}

.form-group select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%234A9FD4' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10l-5 5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 16px center;
  padding-right: 44px;
}

.form-group select option {
  background: var(--bg-card);
  color: var(--text-primary);
}

/* Upload Zone */
.upload-zone {
  position: relative;
  padding: 40px;
  background: var(--bg-card);
  border: 2px dashed var(--border-light);
  border-radius: 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s ease;
}

.upload-zone:hover {
  border-color: var(--sky-blue);
  background: rgba(74, 159, 212, 0.03);
}

.upload-zone.drag-over {
  border-color: var(--sky-blue);
  background: rgba(74, 159, 212, 0.06);
  transform: scale(1.01);
}

.upload-zone input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
}

.upload-zone-content {
  pointer-events: none;
}

.upload-icon {
  width: 40px;
  height: 40px;
  color: var(--sky-blue);
  margin: 0 auto 16px;
}

.upload-text {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.upload-hint {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

.screenshot-preview {
  display: flex;
  gap: 12px;
  margin-top: 16px;
  flex-wrap: wrap;
}

.screenshot-preview-item {
  position: relative;
  width: 120px;
  height: 120px;
  border-radius: 14px;
  overflow: hidden;
  border: 2px solid var(--border-subtle);
  background: var(--bg-card);
}

.screenshot-preview-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.screenshot-remove-btn {
  position: absolute;
  top: 6px;
  right: 6px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: rgba(0,0,0,0.6);
  border: none;
  color: #fff;
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
}

.screenshot-remove-btn:hover {
  background: rgba(220,20,60,0.9);
  transform: scale(1.1);
}

.form-actions {
  display: flex;
  gap: 16px;
  margin-top: 32px;
  flex-wrap: wrap;
}

.form-status {
  margin-top: 16px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
}

/* FAQ */
.faq-list {
  margin-top: 48px;
  max-width: 800px;
}

.faq-item {
  margin-bottom: 12px;
}

.faq-item details {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.faq-item details:hover {
  border-color: var(--border-light);
}

.faq-item summary {
  padding: 20px 24px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

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

.faq-toggle {
  width: 24px;
  height: 24px;
  position: relative;
  flex-shrink: 0;
}

.faq-toggle::before,
.faq-toggle::after {
  content: "";
  position: absolute;
  background: var(--text-tertiary);
  transition: all 0.3s ease;
}

.faq-toggle::before {
  top: 50%;
  left: 0;
  width: 100%;
  height: 2px;
  transform: translateY(-50%);
}

.faq-toggle::after {
  top: 0;
  left: 50%;
  width: 2px;
  height: 100%;
  transform: translateX(-50%);
}

.faq-item details[open] .faq-toggle::after {
  transform: translateX(-50%) rotate(90deg);
  opacity: 0;
}

.faq-item details[open] {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
}

.faq-item details p {
  padding: 0 24px 24px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* Footer */
.footer {
  padding: 64px 0 40px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 24px;
}

.footer-logo {
  width: 44px;
  height: 44px;
  border-radius: 12px;
}

.footer-logo img {
  width: 100%;
  height: 100%;
  border-radius: 12px;
}

.footer-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.01em;
  font-family: var(--font-display);
}

.footer-subtitle {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  margin-top: 2px;
}

.footer-desc {
  font-size: 0.9375rem;
  color: var(--text-tertiary);
  line-height: 1.6;
  max-width: 480px;
  margin-bottom: 24px;
}

.footer-meta {
  display: flex;
  gap: 24px;
  font-size: 0.8125rem;
  color: var(--text-tertiary);
}

/* Scroll Reveal Animation */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 步骤扩展（用途/列表/验证点/警告） ===== */
.step-purpose {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 14px;
  padding: 12px 16px;
  background: rgba(74, 159, 212, 0.05);
  border-left: 3px solid var(--sky-blue-light);
  border-radius: 0 8px 8px 0;
}

.step-list {
  margin: 0 0 16px 0;
  padding-left: 22px;
  list-style: decimal;
}

.step-list li {
  font-size: 0.9375rem;
  color: var(--text-primary);
  line-height: 1.75;
  margin-bottom: 8px;
  padding-left: 4px;
}

.step-list li:last-child {
  margin-bottom: 0;
}

.step-list li strong {
  color: var(--sky-blue-dark);
  font-weight: 600;
}

.step-verify {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-top: 14px;
  padding: 12px 16px;
  background: rgba(245, 200, 66, 0.08);
  border: 1px solid rgba(245, 200, 66, 0.2);
  border-radius: 12px;
}

.verify-label {
  flex-shrink: 0;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #B8860B;
  background: rgba(245, 200, 66, 0.2);
  padding: 3px 10px;
  border-radius: 6px;
  margin-top: 1px;
}

.step-verify p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0;
}

.step-warn {
  margin-top: 12px;
  padding: 12px 16px;
  background: rgba(232, 132, 60, 0.08);
  border: 1px solid rgba(232, 132, 60, 0.25);
  border-radius: 12px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.step-warn strong {
  color: var(--warm-orange);
  font-weight: 700;
}

/* ===== 品牌折叠面板 ===== */
.brand-panels {
  margin-top: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.brand-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 16px;
  overflow: hidden;
  transition: all 0.3s ease;
}

.brand-panel:hover {
  border-color: var(--border-light);
}

.brand-panel summary {
  padding: 18px 22px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

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

.brand-panel .brand-name {
  flex: 1;
}

.brand-panel .faq-toggle {
  width: 20px;
  height: 20px;
  position: relative;
  flex-shrink: 0;
}

.brand-panel .faq-toggle::before,
.brand-panel .faq-toggle::after {
  content: "";
  position: absolute;
  background: var(--text-tertiary);
  transition: all 0.3s ease;
}

.brand-panel .faq-toggle::before {
  top: 50%;
  left: 0;
  width: 100%;
  height: 2px;
  transform: translateY(-50%);
}

.brand-panel .faq-toggle::after {
  top: 0;
  left: 50%;
  width: 2px;
  height: 100%;
  transform: translateX(-50%);
}

.brand-panel[open] .faq-toggle::after {
  transform: translateX(-50%) rotate(90deg);
  opacity: 0;
}

.brand-panel[open] {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
}

.brand-body {
  padding: 0 22px 22px;
}

.brand-body > p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 12px;
}

.brand-body .step-list {
  margin-bottom: 0;
}

/* ===== 品牌专属安装指引面板 ===== */
.brand-guide-panels {
  margin-top: 48px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.brand-guide-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  overflow: hidden;
  transition: all 0.3s ease;
  box-shadow: 0 2px 12px rgba(74, 159, 212, 0.04);
}

.brand-guide-panel:hover {
  border-color: var(--border-light);
  box-shadow: 0 4px 20px rgba(74, 159, 212, 0.08);
}

.brand-guide-panel > summary {
  padding: 22px 28px;
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  background: linear-gradient(135deg, rgba(74, 159, 212, 0.04) 0%, rgba(245, 200, 66, 0.04) 100%);
  transition: background 0.3s ease;
}

.brand-guide-panel > summary::-webkit-details-marker {
  display: none;
}

.brand-guide-panel > summary:hover {
  background: linear-gradient(135deg, rgba(74, 159, 212, 0.08) 0%, rgba(245, 200, 66, 0.08) 100%);
}

.brand-guide-name {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-display);
}

.brand-tag {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 56px;
  height: 28px;
  padding: 0 12px;
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  border-radius: 14px;
  color: #fff;
  font-family: var(--font-sans);
}

.brand-tag-xiaomi {
  background: linear-gradient(135deg, #FF6900 0%, #FF8C00 100%);
}

.brand-tag-honor {
  background: linear-gradient(135deg, #1A73E8 0%, #4A9FD4 100%);
}

.brand-tag-oppo {
  background: linear-gradient(135deg, #1BA784 0%, #2DD4BF 100%);
}

.brand-tag-vivo {
  background: linear-gradient(135deg, #415FFF 0%, #6B8AFF 100%);
}

.brand-guide-panel .faq-toggle {
  width: 20px;
  height: 20px;
  position: relative;
  flex-shrink: 0;
}

.brand-guide-panel .faq-toggle::before,
.brand-guide-panel .faq-toggle::after {
  content: "";
  position: absolute;
  background: var(--text-tertiary);
  transition: all 0.3s ease;
}

.brand-guide-panel .faq-toggle::before {
  top: 50%;
  left: 0;
  width: 100%;
  height: 2px;
  transform: translateY(-50%);
}

.brand-guide-panel .faq-toggle::after {
  top: 0;
  left: 50%;
  width: 2px;
  height: 100%;
  transform: translateX(-50%);
}

.brand-guide-panel[open] .faq-toggle::after {
  transform: translateX(-50%) rotate(90deg);
  opacity: 0;
}

.brand-guide-panel[open] {
  border-color: var(--border-light);
  box-shadow: 0 6px 28px rgba(74, 159, 212, 0.1);
}

.brand-guide-body {
  padding: 8px 28px 32px;
}

/* 阶段分组 */
.guide-phase {
  margin-top: 28px;
  padding-top: 24px;
  border-top: 1px dashed var(--border-subtle);
}

.brand-guide-body .guide-phase:first-child {
  margin-top: 0;
  padding-top: 8px;
  border-top: none;
}

.guide-phase-title {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--sky-blue-dark);
  margin-bottom: 8px;
}

.phase-warn {
  font-size: 0.875rem;
  color: var(--warm-orange);
  line-height: 1.6;
  margin-bottom: 20px;
  padding: 10px 14px;
  background: rgba(232, 132, 60, 0.06);
  border-left: 3px solid var(--warm-orange);
  border-radius: 0 8px 8px 0;
}

/* 单个步骤 */
.guide-step {
  display: flex;
  gap: 18px;
  margin-top: 22px;
}

.guide-step-num {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--sky-blue-dark) 100%);
  color: #fff;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 3px 10px rgba(74, 159, 212, 0.25);
}

.guide-step-body {
  flex: 1;
  min-width: 0;
  padding-top: 4px;
}

.guide-step-body h4 {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.guide-step-body .step-purpose {
  margin-bottom: 12px;
}

.guide-step-body .step-list code {
  background: rgba(74, 159, 212, 0.1);
  color: var(--sky-blue-dark);
  padding: 2px 8px;
  border-radius: 6px;
  font-size: 0.875rem;
  font-family: 'SF Mono', 'Consolas', 'Menlo', monospace;
  word-break: break-all;
}

.step-alt {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  line-height: 1.6;
  margin-top: 8px;
  font-style: italic;
}

/* 找不到品牌提示 */
.brand-guide-tip {
  margin-top: 32px;
  padding: 18px 22px;
  background: rgba(74, 159, 212, 0.05);
  border: 1px solid var(--border-subtle);
  border-radius: 14px;
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.brand-guide-tip .tip-icon {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  color: var(--sky-blue);
  margin-top: 1px;
}

.brand-guide-tip p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin: 0;
}

.brand-guide-tip strong {
  color: var(--sky-blue-dark);
}

/* ===== 权限说明 ===== */
.permissions-section {
  padding: var(--section-padding) 0;
  background: var(--bg-secondary);
}

.permissions-table-wrap {
  margin-top: 40px;
  overflow-x: auto;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  box-shadow: 0 4px 24px rgba(74, 159, 212, 0.06);
}

.permissions-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
}

.permissions-table thead {
  background: linear-gradient(135deg, rgba(74, 159, 212, 0.08) 0%, rgba(245, 200, 66, 0.06) 100%);
}

.permissions-table th {
  padding: 18px 20px;
  text-align: left;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--sky-blue-dark);
  letter-spacing: 0.02em;
  border-bottom: 2px solid var(--border-light);
  white-space: nowrap;
}

.permissions-table td {
  padding: 16px 20px;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.55;
  border-bottom: 1px solid var(--border-subtle);
  vertical-align: top;
}

.permissions-table td:first-child {
  font-weight: 600;
  color: var(--text-primary);
}

.permissions-table td small {
  color: var(--text-tertiary);
  font-weight: 400;
  font-size: 0.8125rem;
}

.permissions-table tbody tr:last-child td {
  border-bottom: none;
}

.permissions-table tbody tr:hover {
  background: var(--bg-card-hover);
}

.permissions-note {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  margin-top: 32px;
}

.permissions-note-item {
  padding: 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
}

.permissions-note-item strong {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 10px;
  font-family: var(--font-display);
}

.permissions-note-item p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ===== 测试任务清单 ===== */
.checklist-section {
  padding: var(--section-padding) 0;
  background: var(--bg-primary);
}

.checklist-groups {
  margin-top: 48px;
  display: flex;
  flex-direction: column;
  gap: 36px;
  max-width: 760px;
}

.checklist-group {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 20px;
  padding: 28px 32px;
}

.checklist-group-title {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--sky-blue-dark);
  margin-bottom: 18px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-subtle);
}

.checklist-items {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.checklist-items label {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  cursor: pointer;
  font-size: 0.9375rem;
  color: var(--text-primary);
  line-height: 1.55;
  padding: 6px 4px;
  border-radius: 8px;
  transition: background 0.2s ease;
}

.checklist-items label:hover {
  background: rgba(74, 159, 212, 0.04);
}

.checklist-items input[type="checkbox"] {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  margin-top: 1px;
  accent-color: var(--sky-blue);
  cursor: pointer;
}

.checklist-items input[type="checkbox"]:checked + span {
  color: var(--text-tertiary);
  text-decoration: line-through;
}

.checklist-items span {
  flex: 1;
  transition: color 0.2s ease;
}

.checklist-actions {
  margin-top: 28px;
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}

.checklist-hint {
  font-size: 0.8125rem;
  color: var(--text-tertiary);
  margin: 0;
}

/* ===== 测试联系人 ===== */
.contact-section {
  padding: var(--section-padding) 0;
  background: var(--bg-secondary);
}

.contact-card {
  margin: 0 auto;
  max-width: 520px;
  padding: 36px;
  background: var(--bg-card);
  border: 1px solid var(--border-light);
  border-radius: 24px;
  display: flex;
  align-items: center;
  gap: 24px;
  box-shadow: 0 8px 32px rgba(74, 159, 212, 0.08);
}

.contact-avatar {
  flex-shrink: 0;
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--sky-blue) 0%, var(--sky-blue-dark) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  box-shadow: 0 6px 18px rgba(74, 159, 212, 0.3);
}

.contact-avatar svg {
  width: 32px;
  height: 32px;
}

.contact-info {
  flex: 1;
  min-width: 0;
}

.contact-name {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.contact-method {
  font-size: 0.9375rem;
  color: var(--sky-blue-dark);
  font-weight: 600;
  margin-bottom: 8px;
  word-break: break-all;
}

.contact-note {
  font-size: 0.875rem;
  color: var(--text-tertiary);
  line-height: 1.55;
  margin: 0;
}

/* ===== 响应式补充 ===== */
@media (max-width: 768px) {
  .permissions-note {
    grid-template-columns: 1fr;
  }

  .checklist-group {
    padding: 22px 20px;
  }

  .contact-card {
    flex-direction: column;
    text-align: center;
    padding: 28px 24px;
  }

  .brand-panel summary {
    padding: 16px 18px;
    font-size: 0.9375rem;
  }

  .brand-body {
    padding: 0 18px 18px;
  }

  .step-list {
    padding-left: 20px;
  }

  .step-verify,
  .step-warn {
    padding: 10px 14px;
  }

  /* 品牌专属指引面板移动端适配 */
  .brand-guide-panel > summary {
    padding: 18px 20px;
    font-size: 0.9375rem;
  }

  .brand-guide-name {
    gap: 8px;
    flex-wrap: wrap;
  }

  .brand-tag {
    min-width: 48px;
    height: 24px;
    font-size: 0.75rem;
    padding: 0 10px;
  }

  .brand-guide-body {
    padding: 8px 20px 24px;
  }

  .guide-step {
    gap: 14px;
  }

  .guide-step-num {
    width: 30px;
    height: 30px;
    font-size: 0.875rem;
  }

  .guide-step-body .step-list code {
    font-size: 0.8125rem;
    padding: 1px 6px;
  }

  .brand-guide-tip {
    padding: 14px 16px;
    gap: 10px;
  }
}

/* Responsive */
@media (max-width: 1024px) {
  .hero-section .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content {
    max-width: 100%;
  }

  .hero-logo {
    max-width: 300px;
    margin-top: 40px;
  }

  .hero-cta {
    justify-content: center;
  }

  .philosophy-grid {
    grid-template-columns: 1fr 1fr;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .about-main {
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  :root {
    --section-padding: clamp(48px, 8vw, 80px);
  }

  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 251, 245, 0.98);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 32px;
    gap: 8px;
    transform: translateX(100%);
    transition: transform 0.3s ease;
  }

  .nav-menu.is-open {
    transform: translateX(0);
  }

  .nav-link {
    padding: 16px 0;
    font-size: 1.125rem;
    border-bottom: 1px solid var(--border-subtle);
    border-radius: 0;
  }

  .nav-link:hover {
    background: none;
    color: var(--sky-blue);
  }

  .hero-section {
    min-height: calc(100vh - 72px - 80px);
    padding-top: 48px;
  }

  .hero-cta {
    flex-direction: column;
    width: 100%;
  }

  .hero-cta .btn {
    width: 100%;
    max-width: 320px;
  }

  .philosophy-grid {
    grid-template-columns: 1fr;
    margin-top: 48px;
  }

  .philosophy-quote {
    margin-top: 48px;
    padding: 36px 24px;
  }

  .about-cards {
    grid-template-columns: 1fr;
  }

  .steps {
    margin-top: 48px;
  }

  .step {
    grid-template-columns: 48px 1fr;
    gap: 20px;
    margin-bottom: 36px;
  }

  .step-num {
    width: 48px;
    height: 48px;
    font-size: 1rem;
  }

  .test-note {
    grid-template-columns: 1fr;
    margin-top: 48px;
    padding-top: 36px;
  }

  .download-box {
    padding: 36px 24px;
  }

  .form-row {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .form-actions {
    flex-direction: column;
  }

  .form-actions .btn {
    width: 100%;
  }

  .footer-meta {
    flex-direction: column;
    gap: 8px;
  }
}

@media (max-width: 480px) {
  .hero-eyebrow {
    font-size: 0.75rem;
    padding: 8px 16px;
  }

  .section-label {
    font-size: 0.6875rem;
  }
}