/* ========================================
   VibeRuns Landing Page - styles.css
   Based on OpenNote design
   ======================================== */

/* ===== @font-face ===== */
@font-face {
  font-family: 'Suisse Intl';
  src: url('fonts/SuisseIntl_Light-s.p.5d8f3eb4.ttf') format('truetype');
  font-weight: 300;
  font-display: swap;
}
@font-face {
  font-family: 'Suisse Intl';
  src: url('fonts/SuisseIntl_Regular-s.p.22cc6049.ttf') format('truetype');
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: 'Suisse Intl';
  src: url('fonts/SuisseIntl_Medium-s.p.1f5f5bcf.ttf') format('truetype');
  font-weight: 500;
  font-display: swap;
}
@font-face {
  font-family: 'Suisse Intl';
  src: url('fonts/SuisseIntl_SemiBold-s.p.91f1e29e.ttf') format('truetype');
  font-weight: 600;
  font-display: swap;
}
@font-face {
  font-family: 'Suisse Intl';
  src: url('fonts/SuisseIntl_Bold-s.p.7195dd21.ttf') format('truetype');
  font-weight: 700;
  font-display: swap;
}
@font-face {
  font-family: 'Clash Display';
  src: url('fonts/ClashDisplay_Variable-s.p.81061a37.ttf') format('truetype');
  font-weight: 200 700;
  font-display: swap;
}
@font-face {
  font-family: 'Clash Grotesk';
  src: url('fonts/ClashGrotesk_Variable-s.p.424c49d9.ttf') format('truetype');
  font-weight: 200 700;
  font-display: swap;
}
@font-face {
  font-family: 'Heming';
  src: url('fonts/Heming_Variable-s.p.23f16957.ttf') format('truetype');
  font-weight: 200 700;
  font-display: swap;
}
@font-face {
  font-family: 'JetBrains Mono';
  src: url('fonts/JetBrainsMono_Variable-s.p.5cc74a9d.ttf') format('truetype');
  font-weight: 100 800;
  font-display: swap;
}
@font-face {
  font-family: 'Iowan Old';
  src: url('fonts/IowanOld-s.p.c5fbfa23.woff2') format('woff2');
  font-weight: 400;
  font-display: swap;
}
@font-face {
  font-family: 'Iowan Old';
  src: url('fonts/IowanOld_Bold-s.p.35baa0ab.ttf') format('truetype');
  font-weight: 700;
  font-display: swap;
}
@font-face {
  font-family: 'Neue Haas Grotesk';
  src: url('fonts/NeueHaasGrotesk_Medium-s.p.1750d2f0.ttf') format('truetype');
  font-weight: 500;
  font-display: swap;
}

/* ===== CSS Variables ===== */
:root {
  --white: #ffffff;
  --black: #171717;
  --neutral-50: #fafafa;
  --neutral-100: #f5f5f5;
  --neutral-200: #e5e5e5;
  --neutral-300: #d4d4d4;
  --neutral-400: #a3a3a3;
  --neutral-500: #737373;
  --neutral-600: #525252;
  --neutral-700: #404040;
  --neutral-800: #262626;
  --neutral-900: #171717;

  --blue-1: rgb(87, 112, 249);
  --blue-2: rgb(218, 239, 248);
  --blue-3: rgb(219, 234, 254);

  --yellow-1: #b45309;
  --yellow-2: #FFF3CD;
  --yellow-3: #FEEABC;

  --pink-1: #DB2777;
  --pink-2: #FCE4EC;

  --green-1: rgb(55, 159, 87);
  --green-2: rgb(216, 255, 228);
  --green-3: rgb(220, 252, 231);

  --bg: #FAF9F6;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-2xl: 32px;

  --font-sans: 'Suisse Intl', ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-display: 'Clash Display', 'Suisse Intl', sans-serif;
  --font-serif: 'Iowan Old', Georgia, serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
}

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

html {
  -webkit-text-size-adjust: 100%;
  line-height: 1.5;
  tab-size: 4;
  font-feature-settings: normal;
  -webkit-tap-highlight-color: transparent;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  line-height: 1.5;
  margin: 0;
  color: var(--neutral-900);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
ul, ol { list-style: none; }

/* ===== Language Toggle ===== */
html[lang="en"] .zh { display: none; }
html[lang="zh"] .en { display: none; }

/* ===== Typography ===== */
.h1 {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 3.75rem);
  font-weight: 500;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.h2 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.h3 {
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 2.5vw, 1.75rem);
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.h4 {
  font-family: var(--font-display);
  font-size: clamp(1.125rem, 1.5vw, 1.375rem);
  font-weight: 500;
  line-height: 1.35;
  letter-spacing: -0.01em;
}

.b1 {
  font-size: 1.125rem;
  line-height: 1.6;
}

.b2 {
  font-size: 1rem;
  line-height: 1.6;
}

.b3 {
  font-size: 0.875rem;
  line-height: 1.5;
}

/* ===== Layout ===== */
.container {
  max-width: 68rem;
  margin: 0 auto;
  padding: 0 1rem;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  background: rgba(250,249,246,0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 68rem;
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--neutral-900);
  color: var(--white);
  border-radius: 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
}

.nav-logo span {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 500;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 0;
}

.nav-link {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 400;
  color: var(--neutral-600);
  border-radius: 8px;
  transition: background 0.15s, color 0.15s;
}

.nav-link:hover {
  background: var(--neutral-100);
  color: var(--neutral-900);
}

.lang-toggle {
  padding: 0.375rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--neutral-500);
  background: transparent;
  border: 1px solid var(--neutral-200);
  border-radius: 6px;
  transition: border-color 0.15s, color 0.15s;
  margin-right: 0.5rem;
}

.lang-toggle:hover {
  border-color: var(--neutral-400);
  color: var(--neutral-900);
}

.nav-cta {
  background: transparent;
  color: var(--neutral-900);
  padding: 0.5rem 1.25rem;
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 500;
  border: 1px solid var(--neutral-300);
  transition: border-color 0.15s, background 0.15s;
}

.nav-cta:hover {
  border-color: var(--neutral-900);
  background: var(--neutral-50);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 0.5rem;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--neutral-900);
  margin: 4px 0;
  transition: all 0.3s;
}

/* ===== Hero ===== */
.hero {
  padding-top: 6rem;
  padding-bottom: 3rem;
  text-align: center;
}

@media (min-width: 1024px) {
  .hero {
    padding-top: 7rem;
    padding-bottom: 4rem;
  }
}

.hero .container {
  max-width: 36.875rem;
}

.hero-illustration {
  max-width: 14rem;
  margin: 0 auto;
  pointer-events: none;
  user-select: none;
}

.hero h1 {
  margin-top: 1.25rem;
  margin-bottom: 2rem;
}

@media (min-width: 1024px) {
  .hero h1 {
    margin-top: 1.5rem;
    margin-bottom: 2.5rem;
  }
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--neutral-900);
  color: var(--white);
  padding: 0.75rem 1.5rem;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 500;
  border: none;
  transition: all 0.2s;
}

.hero-cta:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}

.hero-cta svg {
  width: 20px;
  height: 20px;
}

/* ===== Platform logos ===== */
.uni-section {
  padding: 3rem 0;
  text-align: center;
}

.uni-section p {
  font-size: 0.875rem;
  color: var(--neutral-400);
  margin-bottom: 1.5rem;
}

.uni-logos {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: 2rem;
  opacity: 0.5;
}

.uni-logos img {
  height: 1.5rem;
  object-fit: contain;
}

/* ===== Feature Video / App Preview Section ===== */
.video-hero {
  padding: 2rem 0;
  text-align: center;
}

.video-hero .container {
  max-width: 40rem;
}

.video-hero h2 {
  margin-bottom: 1.5rem;
}

.video-hero video {
  width: 100%;
  border-radius: var(--radius-xl);
  box-shadow: 0 20px 60px rgba(0,0,0,0.08);
}

.app-preview {
  width: 100%;
  border-radius: var(--radius-xl);
  box-shadow: 0 20px 60px rgba(0,0,0,0.08);
  overflow: hidden;
}

.app-preview-inner {
  aspect-ratio: 1 / 1;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--neutral-100);
  color: var(--neutral-400);
}

/* ===== Core Philosophy (Meet Galileo) ===== */
.galileo-section {
  padding: 4rem 0;
}

.galileo-section .container {
  max-width: 36rem;
  text-align: center;
}

.galileo-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--blue-2);
  color: var(--blue-1);
  padding: 0.375rem 0.875rem;
  border-radius: 100px;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.75rem;
}

.galileo-section h3 {
  margin-bottom: 1rem;
  color: var(--blue-1);
}

.galileo-section .b2 {
  color: var(--neutral-500);
}

/* ===== AI Features 3-column ===== */
.ai-features {
  padding: 6rem 0;
}

.ai-features > .container {
  text-align: center;
  margin-bottom: 3rem;
}

.ai-features h2 {
  margin-bottom: 1rem;
}

.ai-grid {
  max-width: 67.75rem;
  margin: 0 auto;
  padding: 0 1rem;
  display: grid;
  gap: 1.5rem;
}

@media (min-width: 1024px) {
  .ai-grid {
    grid-template-columns: 1fr minmax(0, 14rem) 1fr;
  }
}

.ai-side {
  position: relative;
}

.ai-side img {
  position: sticky;
  top: 5rem;
  max-width: 100%;
}

.ai-side img.right {
  margin-left: auto;
}

@media (min-width: 1024px) {
  .ai-side img.right {
    mix-blend-mode: multiply;
  }
}

.ai-center {
  display: flex;
  flex-direction: column;
  gap: 19.75rem;
  max-width: 14.4rem;
  margin: 0 auto;
}

.ai-card {
  text-align: center;
}

.ai-card-media {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-grow: 1;
  margin-bottom: 0.75rem;
}

.ai-card-media img {
  max-width: 100%;
  max-height: 10rem;
}

.ai-card h3 {
  margin-bottom: 0.75rem;
}

.ai-card .b2 {
  color: var(--neutral-500);
  opacity: 0.8;
}

/* ===== Testimonials ===== */
.testimonial {
  padding: 4rem 0;
  text-align: center;
}

.testimonial .container {
  max-width: 36rem;
}

.testimonial h3 {
  font-family: var(--font-serif);
  font-style: italic;
  margin-bottom: 1rem;
}

.testimonial .attribution {
  font-size: 0.875rem;
  color: var(--neutral-500);
}

.stars {
  display: flex;
  justify-content: center;
  gap: 2px;
  margin-bottom: 1rem;
}

.stars svg {
  width: 16px;
  height: 16px;
  fill: #FBBF24;
}

/* ===== Tabs Section ===== */
.tabs-section {
  padding: 6rem 0;
}

.tabs-section .container {
  text-align: center;
}

.tabs-section h2 {
  margin-bottom: 3rem;
}

@media (min-width: 1024px) {
  .tabs-section h2 {
    margin-bottom: 3.5rem;
  }
}

.tabs-bar {
  display: flex;
  justify-content: center;
  gap: 0.25rem;
  margin-bottom: 2rem;
  background: var(--neutral-100);
  padding: 0.25rem;
  border-radius: 10px;
  display: inline-flex;
}

.tab-btn {
  padding: 0.5rem 1.25rem;
  border: none;
  background: transparent;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--neutral-500);
  border-radius: 8px;
  transition: all 0.2s;
}

.tab-btn.active {
  background: var(--white);
  color: var(--neutral-900);
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

.tab-panel {
  display: none;
  max-width: 54.6rem;
  margin: 0 auto;
}

.tab-panel.active {
  display: block;
}

.tab-panel video {
  width: 100%;
  border-radius: var(--radius-xl);
  box-shadow: 0 8px 40px rgba(0,0,0,0.06);
}

.tab-placeholder {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-xl);
  box-shadow: 0 8px 40px rgba(0,0,0,0.06);
  background: var(--neutral-100);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--neutral-400);
}

/* ===== Sticky Cards ===== */
.sticky-section {
  padding: 6rem 0;
}

.sticky-section-head {
  text-align: center;
  margin-bottom: 2rem;
}

.sticky-cards {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 0 4rem;
}

.sticky-card {
  position: sticky;
  top: 7rem;
  width: 18.4375rem;
  min-height: 22.1875rem;
  padding: 2rem 2rem 2rem;
  border-radius: var(--radius-2xl);
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  margin-bottom: 2rem;
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (min-width: 768px) {
  .sticky-card {
    width: 21.5625rem;
    min-height: 26.125rem;
  }
}

@media (min-width: 1024px) {
  .sticky-card {
    top: 9rem;
  }
}

.sticky-card:hover {
  transform: rotate(0deg) scale(1.03) !important;
}

.sticky-card-icon {
  flex-grow: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

.sticky-card-icon img {
  max-width: 80%;
  max-height: 10rem;
}

.sticky-card h3 {
  margin-bottom: 0.75rem;
}

.sticky-card .b2 {
  opacity: 0.8;
}

/* Card colors */
.card-blue { background: var(--blue-3); color: var(--blue-1); }
.card-yellow-2 { background: var(--yellow-2); color: var(--yellow-1); }
.card-yellow-3 { background: var(--yellow-3); color: var(--yellow-1); }
.card-pink { background: var(--pink-2); color: var(--pink-1); }
.card-green { background: var(--green-3); color: var(--green-1); }

/* Card rotations */
.rot-1 { transform: rotate(-10.355deg); }
.rot-2 { transform: rotate(2.391deg); }
.rot-3 { transform: rotate(13.222deg); }
.rot-4 { transform: rotate(-7.758deg); }
.rot-5 { transform: rotate(9.399deg); }

/* ===== Green CTA Section ===== */
.green-section {
  padding: 6rem 0;
  text-align: center;
}

.green-section .container {
  max-width: 40rem;
}

.green-bg-wrapper {
  position: relative;
  border-radius: var(--radius-2xl);
  overflow: hidden;
  padding: 4rem 2rem;
  background: var(--green-3);
}

.green-bg-wrapper .bg-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.3;
}

.green-section h2 {
  position: relative;
  margin-bottom: 1rem;
}

.green-section .b1 {
  position: relative;
  color: var(--neutral-600);
  margin-bottom: 2rem;
}

.green-section .cta-btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--green-1);
  color: var(--white);
  padding: 0.75rem 1.5rem;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 500;
  border: none;
  transition: opacity 0.2s;
}

.green-section .cta-btn:hover { opacity: 0.9; }

/* ===== Footer ===== */
.footer {
  padding: 4rem 0 2rem;
  position: relative;
  overflow: hidden;
}

.footer-visuals {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  margin-bottom: 2rem;
  padding: 0 2rem;
}

.footer-visuals img {
  max-width: 30%;
  max-height: 200px;
  object-fit: contain;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  flex-wrap: wrap;
  gap: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--neutral-200);
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.footer-logo svg { width: 40px; height: 30px; }
.footer-logo span {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 1.125rem;
}

.footer-links {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 0.875rem;
  color: var(--neutral-500);
  transition: color 0.15s;
}

.footer-links a:hover { color: var(--neutral-900); }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1.5rem;
}

.footer-copy {
  font-size: 0.75rem;
  color: var(--neutral-400);
}

.footer-social {
  display: flex;
  gap: 0.75rem;
}

.footer-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: 6px;
  color: var(--neutral-500);
  transition: color 0.15s, background 0.15s;
}

.footer-social a:hover {
  color: var(--neutral-900);
  background: var(--neutral-100);
}

.footer-social svg {
  width: 18px;
  height: 18px;
}

/* ===== Animations ===== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.reveal.d1 { transition-delay: 0.1s; }
.reveal.d2 { transition-delay: 0.2s; }
.reveal.d3 { transition-delay: 0.3s; }

/* ===== Mobile ===== */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }

  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg);
    border: 1px solid var(--neutral-200);
    border-radius: 12px;
    padding: 1rem;
    margin: 0.5rem 1rem;
    gap: 0.25rem;
  }

  .ai-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .ai-side { display: none; }

  .ai-center {
    gap: 4rem;
    max-width: 100%;
  }

  .footer-top {
    flex-direction: column;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }
}