/* ============================================
   白羽大学 Shiroha University - 主样式表
   Shiroha OS Design System v1.0
   ============================================ */

/* === CSS Custom Properties (Design Tokens) === */
:root {
  /* Primary Palette */
  --color-white: #FFFFFF;
  --color-shirone: #F5F0EB;
  --color-polar-blue: #1C3B5E;
  --color-russian-red: #D32F2F;
  --color-island-blue: #81D4FA;
  
  /* Extended Palette */
  --color-polar-dark: #0F2440;
  --color-polar-light: #2A5A8A;
  --color-gold: #C9A96E;
  --color-gold-light: #E8D5B0;
  --color-slate: #2C3E50;
  --color-charcoal: #1a1a2e;
  --color-cream: #FAF7F2;
  --color-soft-gray: #F0EDE8;
  
  /* Text */
  --text-primary: #1a1a2e;
  --text-secondary: #555;
  --text-muted: #888;
  --text-on-dark: #FFFFFF;
  --text-on-dark-muted: rgba(255,255,255,0.7);
  
  /* Typography */
  --font-cn: 'Noto Sans SC', 'Source Han Sans SC', 'Microsoft YaHei', sans-serif;
  --font-jp: 'Noto Sans JP', sans-serif;
  --font-ru: 'PT Serif', 'Times New Roman', serif;
  --font-en: 'Cormorant Garamond', 'Georgia', serif;
  --font-mono: 'JetBrains Mono', 'Consolas', monospace;
  --font-display: 'Cormorant Garamond', 'Georgia', serif;
  
  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 5rem;
  --space-3xl: 8rem;
  
  /* Layout */
  --max-width: 1200px;
  --nav-height: 72px;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  
  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.15);
  --shadow-xl: 0 20px 60px rgba(0,0,0,0.2);
  
  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: 0.6s cubic-bezier(0.34, 1.56, 0.64, 1);
  
  /* Z-index layers */
  --z-nav: 1000;
  --z-loading: 9999;
  --z-modal: 2000;
  --z-shirone: 1500;
  --z-cursor-trail: 9998;
}

/* === CSS Reset === */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-cn);
  color: var(--text-primary);
  background: var(--color-white);
  line-height: 1.7;
  overflow-x: hidden;
  cursor: default;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-island-blue);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

/* === Loading Screen === */
#loading-screen {
  position: fixed;
  inset: 0;
  z-index: var(--z-loading);
  background: #000;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  transition: opacity 0.8s ease, visibility 0.8s ease;
}

#loading-screen.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loading-feather {
  width: 40px;
  height: 120px;
  position: relative;
  animation: feather-fall 2.5s ease-in-out forwards;
  opacity: 0;
}

@keyframes feather-fall {
  0% { transform: translateY(-60vh) rotate(-15deg); opacity: 0; }
  20% { opacity: 1; }
  40% { transform: translateY(-10vh) rotate(5deg); }
  60% { transform: translateY(0) rotate(-5deg); }
  80% { transform: translateY(5vh) rotate(3deg); }
  100% { transform: translateY(10vh) rotate(0deg); opacity: 0.8; }
}

.loading-feather svg {
  width: 100%;
  height: 100%;
  fill: var(--color-white);
}

.loading-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  color: var(--color-white);
  letter-spacing: 0.3em;
  text-align: center;
  margin-top: 2rem;
  opacity: 0;
  animation: fade-in-up 1s 1.5s ease forwards;
}

.loading-subtitle {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
  letter-spacing: 0.2em;
  margin-top: 1.5rem;
  opacity: 0;
  animation: fade-in-up 1s 2.2s ease forwards;
}

.loading-subtitle .dot-anim::after {
  content: '';
  animation: dots 1.5s steps(4, end) infinite;
}

@keyframes dots {
  0% { content: ''; }
  25% { content: '.'; }
  50% { content: '..'; }
  75% { content: '...'; }
  100% { content: ''; }
}

@keyframes fade-in-up {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* === Navigation === */
#main-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-xl);
  transition: background var(--transition-base), box-shadow var(--transition-base);
  background: transparent;
}

#main-nav.scrolled {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-sm);
}

#main-nav.scrolled .nav-logo-text { color: var(--text-primary); }
#main-nav.scrolled .nav-link { color: var(--text-secondary); }
#main-nav.scrolled .nav-link:hover { color: var(--color-russian-red); }

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  text-decoration: none;
}

.nav-logo-icon {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-logo-icon svg { width: 100%; height: 100%; }

.nav-logo-text {
  font-family: var(--font-display);
  font-size: 1.2rem;
  letter-spacing: 0.15em;
  color: var(--text-on-dark);
  transition: color var(--transition-base);
  white-space: nowrap;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  list-style: none;
}

.nav-link {
  text-decoration: none;
  color: var(--text-on-dark-muted);
  font-size: 0.9rem;
  letter-spacing: 0.05em;
  transition: color var(--transition-fast);
  position: relative;
  padding: var(--space-xs) 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-island-blue);
  transition: width var(--transition-base);
}

.nav-link:hover::after { width: 100%; }
.nav-link:hover { color: var(--color-white); }

.nav-link.dropdown-toggle {
  cursor: pointer;
}

.nav-dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  background: rgba(255,255,255,0.98);
  backdrop-filter: blur(20px);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: var(--space-md) 0;
  min-width: 200px;
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  list-style: none;
}

.nav-dropdown.show {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(4px);
}

.nav-dropdown a {
  display: block;
  padding: var(--space-sm) var(--space-lg);
  color: var(--text-primary);
  text-decoration: none;
  font-size: 0.85rem;
  transition: background var(--transition-fast), color var(--transition-fast);
}

.nav-dropdown a:hover {
  background: var(--color-soft-gray);
  color: var(--color-russian-red);
}

.nav-item {
  position: relative;
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}

.mobile-menu-btn span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-on-dark);
  margin: 5px 0;
  transition: all var(--transition-base);
}

#main-nav.scrolled .mobile-menu-btn span { background: var(--text-primary); }

/* === Hero Section === */
.hero {
  position: relative;
  height: 100vh;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-slides {
  position: absolute;
  inset: 0;
}

.hero-slide {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0;
  transition: opacity 1.5s ease;
}

.hero-slide.active { opacity: 1; }

.hero-slide::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, rgba(10,18,32,0.72) 0%, rgba(15,36,64,0.42) 46%, rgba(115,180,220,0.18) 100%),
    linear-gradient(180deg, rgba(255,255,255,0.08) 0%, rgba(15,36,64,0.18) 58%, rgba(8,12,20,0.68) 100%);
}

/* Campus 1 - 应天府: Snow + Red Brick */
.hero-slide-1 {
  background-image: url('../assets/sp/sp-island-hero.jpg');
  background-position: center 35%;
}

/* Campus 2 - 莫斯科港: Aurora + Icebreaker */
.hero-slide-2 {
  background-image: url('../assets/sp/sp-torishiro-sea.jpg');
  background-position: center 42%;
}

/* Campus 3 - 鸟白岛: Sea + Railway */
.hero-slide-3 {
  background-image: url('../assets/sp/sp-summer-veranda.jpg');
  background-position: center 40%;
}

.hero-content {
  position: relative;
  z-index: 2;
  color: var(--color-white);
  max-width: 760px;
  padding: var(--space-xl);
  margin-left: clamp(1rem, 6vw, 6rem);
  border-left: 1px solid rgba(255,255,255,0.42);
  text-shadow: 0 2px 18px rgba(0,0,0,0.25);
}

.hero-content::before {
  content: 'SUMMER ARCHIVE';
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  color: rgba(201,169,110,0.95);
  margin-bottom: var(--space-md);
}

.hero-subtitle-zh {
  font-size: 1rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  margin-bottom: var(--space-md);
  opacity: 0.9;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3rem, 7vw, 5.5rem);
  font-weight: 400;
  letter-spacing: 0.08em;
  line-height: 1.1;
  margin-bottom: var(--space-lg);
}

.hero-quote {
  font-size: 1.15rem;
  font-style: italic;
  opacity: 0.85;
  max-width: 500px;
  margin: 0 auto var(--space-lg);
  line-height: 1.8;
}

.hero-quote::before { content: '\201C'; }
.hero-quote::after { content: '\201D'; }

.hero-scroll-indicator {
  position: absolute;
  bottom: var(--space-xl);
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-on-dark-muted);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-10px); }
  60% { transform: translateX(-50%) translateY(-5px); }
}

.hero-dots {
  position: absolute;
  bottom: var(--space-xl);
  right: var(--space-xl);
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.hero-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: rgba(255,255,255,0.3);
  cursor: pointer;
  transition: all var(--transition-base);
}

.hero-dot.active {
  background: var(--color-white);
  box-shadow: 0 0 12px rgba(255,255,255,0.5);
}

/* === Section Common === */
.section {
  padding: var(--space-3xl) var(--space-xl);
  position: relative;
}

.section-dark {
  background: var(--color-polar-dark);
  color: var(--text-on-dark);
}

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

.section-header {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section-label {
  font-size: 0.8rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: var(--space-sm);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 400;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
  line-height: 1.3;
}

.section-dark .section-title { color: var(--text-on-dark); }

.section-subtitle {
  font-size: 1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

.section-dark .section-subtitle { color: var(--text-on-dark-muted); }

.section-divider {
  width: 60px;
  height: 2px;
  background: var(--color-gold);
  margin: var(--space-lg) auto;
}

/* === Grand Motto Section === */
.motto-grand {
  background:
    linear-gradient(90deg, rgba(15,36,64,0.96), rgba(15,36,64,0.82)),
    url('../assets/sp/sp-shiroha-memory.png') center / cover no-repeat;
  color: var(--text-on-dark);
  padding: clamp(5rem, 10vw, 9rem) var(--space-xl);
  position: relative;
  overflow: hidden;
}

.motto-grand::before,
.motto-grand::after {
  content: '';
  position: absolute;
  left: clamp(1.5rem, 6vw, 5rem);
  right: clamp(1.5rem, 6vw, 5rem);
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(201,169,110,0.7), transparent);
}

.motto-grand::before { top: clamp(2rem, 4vw, 3.5rem); }
.motto-grand::after { bottom: clamp(2rem, 4vw, 3.5rem); }

.motto-grand-inner::after {
  content: 'Naruse Shiroha / Memory of Summer';
  position: absolute;
  right: 0;
  bottom: -2.8rem;
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3vw, 2.6rem);
  color: rgba(255,255,255,0.12);
  font-style: italic;
  pointer-events: none;
}

.motto-grand-inner {
  max-width: 1180px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.motto-grand-kicker {
  display: flex;
  justify-content: space-between;
  gap: var(--space-xl);
  color: rgba(201,169,110,0.82);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  margin-bottom: clamp(2rem, 5vw, 4rem);
}

.motto-grand-cn {
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 9vw, 8.5rem);
  font-weight: 300;
  line-height: 1.08;
  letter-spacing: 0.08em;
  color: #fff;
  max-width: 10em;
  text-wrap: balance;
}

.motto-grand-en {
  font-family: var(--font-serif);
  font-size: clamp(1.3rem, 2.8vw, 2.4rem);
  font-style: italic;
  color: rgba(255,255,255,0.72);
  line-height: 1.55;
  max-width: 760px;
  margin-top: clamp(1.5rem, 4vw, 3rem);
}

.motto-grand-note {
  display: grid;
  grid-template-columns: 10rem minmax(0, 1fr);
  gap: var(--space-xl);
  align-items: start;
  margin-top: clamp(2.5rem, 5vw, 4rem);
  padding-top: var(--space-xl);
  border-top: 1px solid rgba(201,169,110,0.28);
  max-width: 860px;
}

.motto-grand-seal {
  font-family: var(--font-mono);
  color: var(--color-gold);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  line-height: 1.8;
}

.motto-grand-note p {
  color: rgba(255,255,255,0.66);
  line-height: 1.95;
  margin: 0;
}

.motto-archive-line {
  max-width: 860px;
  margin-top: 1.2rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255,255,255,0.14);
  color: rgba(201,169,110,0.78);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  line-height: 1.9;
}

@media (max-width: 760px) {
  .motto-grand { padding-left: var(--space-md); padding-right: var(--space-md); }
  .motto-grand-kicker { display: block; line-height: 2; }
  .motto-grand-cn { letter-spacing: 0.04em; }
  .motto-grand-note { grid-template-columns: 1fr; gap: var(--space-md); }
  .motto-archive-line { letter-spacing: 0.06em; }
}

/* === About Section === */
.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
  max-width: var(--max-width);
  margin: 0 auto;
}

.about-card {
  background: var(--color-white);
  border-radius: var(--radius-md);
  padding: var(--space-xl);
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
  cursor: pointer;
}

.about-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.about-card-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto var(--space-md);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--color-cream);
}

.about-card-icon svg {
  width: 28px;
  height: 28px;
  stroke: var(--color-russian-red);
}

.about-card h3 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  margin-bottom: var(--space-sm);
  letter-spacing: 0.03em;
}

.about-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* === Mission Statement === */
.mission-block {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  padding: var(--space-3xl) 0;
}

.mission-quote {
  font-family: var(--font-display);
  font-size: clamp(1.3rem, 2.5vw, 1.8rem);
  line-height: 1.8;
  color: var(--text-primary);
  position: relative;
  padding: var(--space-xl);
}

.mission-quote::before {
  content: '\201C';
  font-size: 5rem;
  color: var(--color-gold-light);
  position: absolute;
  top: -20px;
  left: -20px;
  font-family: var(--font-display);
  line-height: 1;
}

.mission-multilang {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-xl);
  margin-top: var(--space-xl);
}

.mission-lang {
  font-size: 0.9rem;
  color: var(--text-muted);
}

.mission-lang .lang-label {
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-right: var(--space-sm);
}

/* === Campuses Section === */
.campuses-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
}

.campus-card {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  height: 480px;
  cursor: pointer;
  group: true;
}

.campus-card-image {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  transition: transform 0.8s ease;
}

.campus-card:hover .campus-card-image {
  transform: scale(1.05);
}

.campus-card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(15,36,64,0.85) 0%, rgba(15,36,64,0.3) 50%, rgba(15,36,64,0.1) 100%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: var(--space-xl);
  color: var(--text-on-dark);
}

.campus-card-tag {
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-island-blue);
  margin-bottom: var(--space-sm);
}

.campus-card h3 {
  font-family: var(--font-display);
  font-size: 1.6rem;
  margin-bottom: var(--space-sm);
  letter-spacing: 0.05em;
}

.campus-card p {
  font-size: 0.9rem;
  opacity: 0.8;
  line-height: 1.6;
}

/* === Stats Bar === */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-2xl) 0;
}

.stat-item {
  text-align: center;
}

.stat-number {
  font-family: var(--font-display);
  font-size: clamp(2rem, 3.5vw, 3rem);
  color: var(--color-russian-red);
  line-height: 1;
  margin-bottom: var(--space-sm);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  letter-spacing: 0.05em;
}

/* === Academic Section === */
.academic-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-lg);
  max-width: var(--max-width);
  margin: 0 auto;
}

.academic-card {
  background: var(--color-white);
  border-left: 3px solid var(--color-russian-red);
  padding: var(--space-lg);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  transition: all var(--transition-base);
}

.academic-card:hover {
  box-shadow: var(--shadow-md);
  border-left-color: var(--color-island-blue);
}

.academic-card h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  margin-bottom: var(--space-sm);
  letter-spacing: 0.03em;
}

.academic-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.academic-card .tag {
  display: inline-block;
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-russian-red);
  margin-top: var(--space-sm);
}

/* === Festivals / Campus Life === */
.festivals-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
  max-width: var(--max-width);
  margin: 0 auto;
}

.festival-card {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  height: 360px;
  cursor: pointer;
}

.festival-card-image {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  transition: transform 0.6s ease;
}

.festival-card:hover .festival-card-image {
  transform: scale(1.05);
}

.festival-card-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(15,36,64,0.9) 0%, rgba(15,36,64,0.2) 60%);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: var(--space-lg);
  color: var(--text-on-dark);
}

.festival-season {
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  margin-bottom: var(--space-sm);
}

.festival-card h3 {
  font-family: var(--font-display);
  font-size: 1.3rem;
  margin-bottom: var(--space-xs);
}

.festival-card .festival-date {
  font-size: 0.8rem;
  opacity: 0.7;
  margin-bottom: var(--space-sm);
}

.festival-card p {
  font-size: 0.85rem;
  opacity: 0.8;
  line-height: 1.5;
}

/* === Quote Block === */
.quote-block {
  text-align: center;
  padding: var(--space-3xl) var(--space-xl);
  position: relative;
}

.quote-block .quote-text {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-style: italic;
  line-height: 1.6;
  max-width: 700px;
  margin: 0 auto;
  color: var(--text-primary);
}

.quote-block .quote-author {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: var(--space-md);
  letter-spacing: 0.1em;
}

/* === Shiroha Guide === */
#shiroha-guide {
  position: fixed;
  bottom: 30px;
  right: 30px;
  z-index: var(--z-shirone);
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--transition-base);
}

#shiroha-guide.visible {
  opacity: 1;
  pointer-events: auto;
}

.shiroha-bubble {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-lg);
  padding: var(--space-md) var(--space-lg);
  box-shadow: var(--shadow-lg);
  max-width: 260px;
  position: absolute;
  bottom: 90px;
  right: 0;
  font-size: 0.85rem;
  line-height: 1.6;
  color: var(--text-primary);
  animation: bubble-in 0.5s ease;
}

.shiroha-bubble::after {
  content: '';
  position: absolute;
  bottom: -8px;
  right: 24px;
  width: 16px;
  height: 16px;
  background: rgba(255,255,255,0.95);
  transform: rotate(45deg);
  box-shadow: 2px 2px 4px rgba(0,0,0,0.05);
}

@keyframes bubble-in {
  from { opacity: 0; transform: translateY(10px) scale(0.95); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

.shiroha-avatar {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--color-polar-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-base);
  position: relative;
}

.shiroha-avatar:hover {
  transform: scale(1.1);
}

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

/* === Cursor Trail (Feathers / Snowflakes) === */
.cursor-trail {
  position: fixed;
  pointer-events: none;
  z-index: var(--z-cursor-trail);
  animation: trail-fade 1.5s ease-out forwards;
}

@keyframes trail-fade {
  0% { opacity: 1; transform: translate(0, 0) rotate(0deg) scale(1); }
  100% { opacity: 0; transform: translate(var(--drift-x), var(--drift-y)) rotate(var(--spin)) scale(0.3); }
}

/* === Footer === */
.site-footer {
  background: var(--color-polar-dark);
  color: var(--text-on-dark-muted);
  padding: var(--space-3xl) var(--space-xl) var(--space-xl);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
  max-width: var(--max-width);
  margin: 0 auto;
}

.footer-brand h3 {
  font-family: var(--font-display);
  color: var(--text-on-dark);
  font-size: 1.3rem;
  margin-bottom: var(--space-sm);
  letter-spacing: 0.1em;
}

.footer-brand p {
  font-size: 0.85rem;
  line-height: 1.7;
}

.footer-col h4 {
  color: var(--text-on-dark);
  font-size: 0.8rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-bottom: var(--space-md);
}

.footer-col a {
  display: block;
  color: var(--text-on-dark-muted);
  text-decoration: none;
  font-size: 0.85rem;
  padding: var(--space-xs) 0;
  transition: color var(--transition-fast);
}

.footer-col a:hover {
  color: var(--color-island-blue);
}

.footer-bottom {
  max-width: var(--max-width);
  margin: var(--space-2xl) auto 0;
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255,255,255,0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
}

.footer-quote {
  font-style: italic;
  color: var(--color-gold);
}

/* === Page Header (for subpages) === */
.page-header {
  height: 50vh;
  min-height: 350px;
  background-size: cover;
  background-position: center;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.page-header::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(15,36,64,0.6);
}

.page-header-content {
  position: relative;
  z-index: 1;
  text-align: center;
  color: var(--text-on-dark);
}

.page-header-content h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.5rem);
  letter-spacing: 0.08em;
  margin-bottom: var(--space-sm);
}

.page-header-content p {
  font-size: 1rem;
  opacity: 0.8;
}

/* === Content Sections for Subpages === */
.content-section {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl);
}

.content-section h2 {
  font-family: var(--font-display);
  font-size: 1.8rem;
  margin-bottom: var(--space-lg);
  letter-spacing: 0.03em;
}

.content-section p {
  font-size: 1rem;
  line-height: 1.9;
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.content-grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: center;
}

.content-grid-2 img {
  width: 100%;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
}

/* === Season Badge === */
.season-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-md);
  border-radius: 50px;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
}

.season-spring { background: #FCE4EC; color: #C2185B; }
.season-summer { background: #E0F7FA; color: #006064; }
.season-autumn { background: #FFF3E0; color: #E65100; }
.season-winter { background: #E8EAF6; color: #283593; }

/* === Buttons === */
.btn {
  display: inline-block;
  padding: var(--space-sm) var(--space-xl);
  border: 1px solid currentColor;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-transform: uppercase;
  background: transparent;
  font-family: var(--font-cn);
}

.btn-primary {
  background: var(--color-russian-red);
  border-color: var(--color-russian-red);
  color: var(--color-white);
}

.btn-primary:hover {
  background: #B71C1C;
  border-color: #B71C1C;
}

.btn-outline {
  border-color: var(--color-white);
  color: var(--color-white);
}

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

.btn-outline-dark {
  border-color: var(--text-primary);
  color: var(--text-primary);
}

.btn-outline-dark:hover {
  background: var(--text-primary);
  color: var(--color-white);
}

/* === Back to Top === */
.back-to-top {
  position: fixed;
  bottom: 30px;
  left: 30px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-white);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: var(--z-nav);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  border: none;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

/* === 404 Page === */
.not-found-page {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--color-polar-dark);
  color: var(--text-on-dark);
  position: relative;
  overflow: hidden;
}

.not-found-page .bg-image {
  position: absolute;
  inset: 0;
  background-image: url('../assets/sp/sp-torishiro-sea.jpg');
  background-size: cover;
  background-position: center;
  opacity: 0.3;
}

.not-found-content {
  position: relative;
  z-index: 1;
  max-width: 500px;
  padding: var(--space-xl);
}

.not-found-content h1 {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 6vw, 4rem);
  color: var(--color-island-blue);
  margin-bottom: var(--space-md);
  letter-spacing: 0.1em;
}

.not-found-content .subtitle {
  font-size: 1rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-gold);
  margin-bottom: var(--space-xl);
}

.not-found-content .quote {
  font-size: 1rem;
  line-height: 1.8;
  opacity: 0.7;
  margin-bottom: var(--space-xl);
  font-style: italic;
}

/* === Animated Elements === */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* === Mobile Navigation Overlay === */
.mobile-nav-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15,36,64,0.98);
  z-index: 1999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

.mobile-nav-overlay.show {
  opacity: 1;
  visibility: visible;
}

.mobile-nav-overlay a {
  color: var(--text-on-dark);
  text-decoration: none;
  font-size: 1.2rem;
  letter-spacing: 0.1em;
  transition: color var(--transition-fast);
}

.mobile-nav-overlay a:hover { color: var(--color-island-blue); }

.mobile-nav-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: none;
  border: none;
  color: var(--text-on-dark);
  font-size: 2rem;
  cursor: pointer;
}

/* === Music Box Click Ripple === */
.click-ripple {
  position: fixed;
  pointer-events: none;
  z-index: 9997;
  border-radius: 50%;
  animation: ripple-expand 0.6s ease-out forwards;
}

@keyframes ripple-expand {
  0% { width: 0; height: 0; opacity: 0.5; border-width: 2px; }
  100% { width: 60px; height: 60px; opacity: 0; border-width: 0.5px; margin-left: -30px; margin-top: -30px; }
}

/* === Responsive Design === */
@media (max-width: 1024px) {
  .campuses-grid { grid-template-columns: 1fr; }
  .campus-card { height: 350px; }
  .festivals-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .content-grid-2 { grid-template-columns: 1fr; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  :root { --nav-height: 60px; }
  .nav-links { display: none; }
  .mobile-menu-btn { display: block; }
  #main-nav { padding: 0 var(--space-md); }
  .section { padding: var(--space-2xl) var(--space-md); }
  .hero-title { font-size: clamp(2rem, 6vw, 3rem); }
  .festivals-grid { grid-template-columns: 1fr; }
  .festival-card { height: 280px; }
  .footer-grid { grid-template-columns: 1fr; }
  .footer-bottom { flex-direction: column; gap: var(--space-md); text-align: center; }
  .stats-bar { grid-template-columns: repeat(2, 1fr); gap: var(--space-md); }
  .about-grid { grid-template-columns: 1fr; }
  .academic-grid { grid-template-columns: 1fr; }
  .campuses-grid { grid-template-columns: 1fr; }
}

/* === Language Switcher === */
.lang-switch { display: block; color: var(--text-on-dark-muted); text-decoration: none; font-size: 0.85rem; padding: var(--space-xs) 0; transition: color var(--transition-fast); cursor: pointer; }
.lang-switch:hover { color: var(--color-island-blue); }
.lang-switch.active { color: var(--color-gold); }


/* ============================================
   Shiroha OS Dark Mode (body.os-mode)
   ============================================ */
body.os-mode { background: #080C14; color: #81D4FA; }
body.os-mode #main-nav { background: rgba(8,12,20,0.95) !important; border-bottom: 1px solid rgba(129,212,250,0.08); }
body.os-mode #main-nav .nav-brand .nav-logo-text { color: #81D4FA !important; }
body.os-mode #main-nav .nav-link { color: rgba(129,212,250,0.65) !important; }
body.os-mode #main-nav .nav-link:hover { color: #81D4FA !important; }
body.os-mode #bgm-player { background: rgba(8,12,20,0.92) !important; border: 1px solid rgba(129,212,250,0.1); box-shadow: none !important; }
body.os-mode #bgm-player span { color: #5a7898 !important; }
body.os-mode #main-nav .nav-link.active { color: #81D4FA !important; }
body.os-mode #main-nav.scrolled { background: rgba(8,12,20,0.98) !important; }
body.os-mode .mobile-nav-overlay { background: rgba(8,12,20,0.98); }
body.os-mode .mobile-nav-overlay a { color: #81D4FA; }
body.os-mode .site-footer { background: #060A10; border-top: 1px solid rgba(129,212,250,0.06); color: rgba(129,212,250,0.5); }
body.os-mode .site-footer a { color: rgba(129,212,250,0.6); }
body.os-mode .site-footer h3, body.os-mode .site-footer h4 { color: #81D4FA; }
body.os-mode #bgm-player { background: rgba(8,12,20,0.92) !important; border: 1px solid rgba(129,212,250,0.1); }
body.os-mode #bgm-player span { color: rgba(129,212,250,0.7) !important; }
body.os-mode #bgm-btn { background: rgba(129,212,250,0.12) !important; color: #81D4FA !important; }
body.os-mode .back-to-top { background: rgba(8,12,20,0.85); color: #81D4FA; border-color: rgba(129,212,250,0.2); }
body.os-mode .shiroha-bubble { background: rgba(8,12,20,0.9); color: #81D4FA; border-color: rgba(129,212,250,0.1); }
body.os-mode .mobile-menu-btn span { background: #81D4FA; }

/* BGM should not block page links; only the round control remains clickable. */
#bgm-player {
  pointer-events: none;
}

#bgm-btn {
  pointer-events: auto;
}

body.os-mode #bgm-player {
  top: 86px !important;
  right: 16px !important;
  bottom: auto !important;
  left: auto !important;
  transform: none !important;
}

/* Shiroha OS is a self-contained interface; hide the normal site footer there. */
body.os-mode .site-footer {
  display: none !important;
}


/* === Summer Archive trial theme === */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: radial-gradient(circle at 72% 18%, rgba(255,255,255,0.28), transparent 24%), linear-gradient(180deg, transparent 78%, rgba(250,247,242,0.12));
}

.campus-card-image {
  filter: saturate(1.08) contrast(1.02);
}

.campus-card-overlay {
  background: linear-gradient(180deg, transparent 0%, rgba(15,36,64,0.18) 24%, rgba(8,12,20,0.84) 100%);
}


/* === Summer Archive Unified Visual Layer === */
:root {
  --archive-blue: #6CBFE8;
  --archive-mist: #F6FBFF;
  --archive-ink: #0F2440;
  --archive-line: rgba(28,59,94,0.12);
  --archive-paper: rgba(255,255,255,0.82);
  --archive-shadow: 0 18px 48px rgba(15,36,64,0.08);
}

body:not(.os-mode) {
  background:
    linear-gradient(180deg, rgba(246,251,255,0.72) 0%, rgba(250,247,242,0.86) 42%, #fff 100%);
}

body:not(.os-mode)::before {
  content: '';
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    linear-gradient(90deg, rgba(108,191,232,0.035) 1px, transparent 1px),
    linear-gradient(180deg, rgba(201,169,110,0.035) 1px, transparent 1px);
  background-size: 56px 56px;
  opacity: 0.55;
}

body:not(.os-mode) #main-nav.scrolled {
  background: rgba(255,255,255,0.82);
  border-bottom: 1px solid rgba(28,59,94,0.08);
  box-shadow: 0 8px 30px rgba(15,36,64,0.06);
}

body:not(.os-mode) #main-nav.scrolled .nav-logo-text {
  color: var(--archive-ink);
}

body:not(.os-mode) #main-nav.scrolled .nav-link.active,
body:not(.os-mode) #main-nav.scrolled .nav-link:hover {
  color: var(--color-russian-red);
}

body:not(.os-mode) .nav-link::after {
  background: linear-gradient(90deg, var(--archive-blue), var(--color-gold));
}

body:not(.os-mode) .section-label,
body:not(.os-mode) .record-kicker,
body:not(.os-mode) .subtitle,
body:not(.os-mode) .dept,
body:not(.os-mode) .date {
  color: var(--color-russian-red);
}

body:not(.os-mode) .section-title,
body:not(.os-mode) .content-section h2,
body:not(.os-mode) .page-header-content h1 {
  text-shadow: 0 1px 0 rgba(255,255,255,0.18);
}

body:not(.os-mode) .page-header {
  isolation: isolate;
}

body:not(.os-mode) .page-header::after {
  background:
    linear-gradient(90deg, rgba(8,12,20,0.66), rgba(15,36,64,0.42), rgba(108,191,232,0.2)),
    linear-gradient(180deg, rgba(255,255,255,0.06), rgba(8,12,20,0.56));
}

body:not(.os-mode) .page-header-content::before {
  content: 'SHIROHA ARCHIVE';
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.22em;
  color: rgba(201,169,110,0.9);
  margin-bottom: var(--space-md);
}

body:not(.os-mode) .page-header-content h1 {
  font-weight: 400;
}

body:not(.os-mode) .btn {
  border-radius: 0;
  border-width: 1px;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

body:not(.os-mode) .btn::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--color-gold);
  opacity: 0.85;
}

body:not(.os-mode) .btn-outline {
  background: rgba(255,255,255,0.08);
}

body:not(.os-mode) .btn-outline:hover,
body:not(.os-mode) .btn-outline-dark:hover {
  background: var(--archive-ink);
  border-color: var(--archive-ink);
  color: #fff;
  box-shadow: 0 10px 26px rgba(15,36,64,0.18);
}

body:not(.os-mode) .about-card,
body:not(.os-mode) .academic-card,
body:not(.os-mode) .faculty-card,
body:not(.os-mode) .institute-card,
body:not(.os-mode) .alum-card,
body:not(.os-mode) .adm-block,
body:not(.os-mode) .policy-card,
body:not(.os-mode) .unit-card,
body:not(.os-mode) .president-record,
body:not(.os-mode) .president-portrait,
body:not(.os-mode) .club-directory,
body:not(.os-mode) .content-grid-2 img {
  border: 1px solid rgba(28,59,94,0.1) !important;
  box-shadow: var(--archive-shadow) !important;
}

body:not(.os-mode) .about-card,
body:not(.os-mode) .academic-card,
body:not(.os-mode) .faculty-card,
body:not(.os-mode) .institute-card,
body:not(.os-mode) .alum-card,
body:not(.os-mode) .adm-block,
body:not(.os-mode) .policy-card,
body:not(.os-mode) .unit-card,
body:not(.os-mode) .president-record,
body:not(.os-mode) .president-portrait {
  background:
    linear-gradient(180deg, rgba(255,255,255,0.94), rgba(255,255,255,0.82)) !important;
}

body:not(.os-mode) .about-card:hover,
body:not(.os-mode) .academic-card:hover,
body:not(.os-mode) .faculty-card:hover,
body:not(.os-mode) .institute-card:hover,
body:not(.os-mode) .alum-card:hover {
  transform: translateY(-3px);
  border-color: rgba(108,191,232,0.3) !important;
}

body:not(.os-mode) .about-card-icon {
  background: linear-gradient(135deg, rgba(108,191,232,0.18), rgba(201,169,110,0.13));
  color: var(--archive-ink);
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.62);
}

body:not(.os-mode) .special,
body:not(.os-mode) .note-box,
body:not(.os-mode) .program-note,
body:not(.os-mode) .club-policy,
body:not(.os-mode) .testimonial,
body:not(.os-mode) .skill-box {
  background: linear-gradient(180deg, rgba(246,251,255,0.9), rgba(250,247,242,0.92)) !important;
  border-color: rgba(201,169,110,0.28) !important;
}

body:not(.os-mode) .campus-card,
body:not(.os-mode) .festival-card {
  border: 1px solid rgba(255,255,255,0.2);
  box-shadow: 0 18px 45px rgba(15,36,64,0.18);
}

body:not(.os-mode) .campus-card-tag,
body:not(.os-mode) .festival-season {
  letter-spacing: 0.12em;
  text-shadow: 0 1px 10px rgba(0,0,0,0.28);
}

body:not(.os-mode) .site-footer {
  background:
    linear-gradient(180deg, #0F2440 0%, #091827 100%);
  border-top: 1px solid rgba(201,169,110,0.18);
}

body:not(.os-mode) .footer-brand h3::after {
  content: ' / Summer Archive';
  color: rgba(201,169,110,0.72);
  font-family: var(--font-display);
  font-style: italic;
  letter-spacing: 0.05em;
}

body:not(.os-mode) .footer-bottom {
  gap: 1rem;
  flex-wrap: wrap;
}

body:not(.os-mode) .footer-bottom::after {
  content: 'ROUTE: YT-2048 / MP-1221 / T-0831';
  color: rgba(201,169,110,0.48);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.14em;
}

body:not(.os-mode) .festival-image {
  border: 1px solid rgba(255,255,255,0.72);
  outline: 1px solid rgba(28,59,94,0.08);
}

body:not(.os-mode) .festival-file,
body:not(.os-mode) .campus-archive-note strong {
  text-shadow: 0 1px 0 rgba(255,255,255,0.32);
}

body:not(.os-mode) .back-to-top,
body:not(.os-mode) #bgm-player {
  border: 1px solid rgba(28,59,94,0.12) !important;
  box-shadow: 0 12px 34px rgba(15,36,64,0.12) !important;
}

body:not(.os-mode) .motto-grand {
  border-top: 1px solid rgba(201,169,110,0.2);
  border-bottom: 1px solid rgba(201,169,110,0.2);
}