/* =============================================
   ANDY ZHANG — Personal Website
   Theme: Berkeley Blue & Gold
   ============================================= */

/* ── RESET & BASE ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  /* Berkeley Blue & Gold palette */
  --blue:        #003262;   /* Berkeley Blue */
  --blue-mid:    #0057a8;
  --blue-light:  #3b82f6;
  --gold:        #FDB515;   /* Berkeley Gold */
  --gold-light:  #ffd166;
  --gold-pale:   #fff3cc;

  /* Dark surface */
  --bg:          #050d1a;
  --bg2:         #0a1628;
  --bg3:         #0f1f38;
  --surface:     rgba(0, 50, 98, 0.25);
  --surface2:    rgba(0, 50, 98, 0.15);
  --border:      rgba(253, 181, 21, 0.18);
  --border2:     rgba(0, 87, 168, 0.35);

  /* Text */
  --text:        #e8f0fe;
  --text-muted:  #8da4c0;
  --text-dim:    #4a6080;

  /* Gradients */
  --grad:        linear-gradient(135deg, var(--blue-light), var(--gold));
  --grad-hero:   linear-gradient(135deg, #0057a8 0%, #003262 40%, #1a0a00 70%, #7a5000 100%);

  --radius:  12px;
  --radius-lg: 20px;
  --shadow:  0 8px 32px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 30px rgba(253,181,21,0.12);
}

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; }

.mono { font-family: 'JetBrains Mono', monospace; }

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--blue-mid); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--gold); }

/* ── GRADIENT TEXT ── */
.gradient-text {
  background: var(--grad);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.psyduck-text {
  background: linear-gradient(90deg, var(--gold), #ff9f0a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── GLASS CARD ── */
.glass-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

/* ── BUTTONS ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 26px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.25s ease;
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--blue-mid), var(--gold));
  color: #fff;
  box-shadow: 0 4px 20px rgba(253,181,21,0.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(253,181,21,0.4); }

.btn-secondary {
  background: transparent;
  border: 1.5px solid var(--border);
  color: var(--text);
}
.btn-secondary:hover { border-color: var(--gold); color: var(--gold); transform: translateY(-2px); }

.btn-nav {
  background: linear-gradient(135deg, var(--blue-mid), var(--gold));
  color: #fff;
  padding: 8px 18px;
  font-size: 0.82rem;
  border-radius: 6px;
}
.btn-nav:hover { opacity: 0.85; }

/* ============================================
   NAV
   ============================================ */
.nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 0 5%;
  height: 64px;
  display: flex;
  align-items: center;
  transition: background 0.3s, box-shadow 0.3s;
}
.nav.scrolled {
  background: rgba(5, 13, 26, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 1px 0 var(--border);
}
.nav-inner {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-size: 1.2rem;
  font-weight: 700;
  background: none;
  letter-spacing: -0.5px;
  display: flex;
  align-items: center;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
}
.nav-link {
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 0.87rem;
  color: var(--text-muted);
  transition: color 0.2s, background 0.2s;
}
.nav-link:hover, .nav-link.active {
  color: var(--gold);
  background: rgba(253,181,21,0.08);
}
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-hamburger span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: all 0.3s;
}

/* ============================================
   HERO
   ============================================ */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 100px 5% 60px;
  position: relative;
  overflow: hidden;
  gap: 60px;
}

.hero-bg-mesh {
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 60% at 10% 20%, rgba(0,87,168,0.35) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 90% 80%, rgba(253,181,21,0.15) 0%, transparent 55%),
    radial-gradient(ellipse 40% 40% at 70% 10%, rgba(0,50,98,0.4) 0%, transparent 50%);
  animation: meshFloat 10s ease-in-out infinite alternate;
}
@keyframes meshFloat {
  0%   { opacity: 0.7; transform: scale(1) rotate(0deg); }
  100% { opacity: 1;   transform: scale(1.05) rotate(1deg); }
}

.hero > * { position: relative; z-index: 1; }

.hero-content { flex: 1; max-width: 560px; }
.hero-visual   { flex: 1; max-width: 480px; }

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 20px;
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 14px;
  border-radius: 100px;
  font-size: 0.78rem;
  font-weight: 600;
}
.badge-available {
  background: rgba(34,197,94,0.12);
  border: 1px solid rgba(34,197,94,0.3);
  color: #4ade80;
}
.badge-dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: #4ade80;
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.5; transform: scale(1.4); }
}
.badge-study {
  background: rgba(253,181,21,0.1);
  border: 1px solid rgba(253,181,21,0.3);
  color: var(--gold);
}

.hero-greeting {
  font-size: 0.9rem;
  color: var(--gold);
  letter-spacing: 0.05em;
  margin-bottom: 10px;
}
.hero-name {
  font-size: clamp(2.6rem, 5vw, 4rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -1.5px;
  margin-bottom: 16px;
}
.hero-title-wrapper {
  font-family: 'JetBrains Mono', monospace;
  font-size: 1.1rem;
  color: var(--blue-light);
  margin-bottom: 20px;
  height: 1.5em;
}
.cursor {
  animation: blink 1s step-end infinite;
  color: var(--gold);
}
@keyframes blink { 0%, 100% { opacity: 1; } 50% { opacity: 0; } }

.hero-description {
  color: var(--text-muted);
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 480px;
}
.hero-description strong { color: var(--text); }

.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 40px; }

.hero-stats {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}
.stat { text-align: center; }
.stat-num { font-size: 1.4rem; font-weight: 800; display: block; }
.stat-label { font-size: 0.72rem; color: var(--text-muted); text-transform: uppercase; letter-spacing: 0.08em; }
.stat-divider { width: 1px; height: 36px; background: var(--border2); }

/* Code block in hero */
.code-block {
  overflow: hidden;
  box-shadow: var(--shadow), var(--shadow-glow);
}
.code-header {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 12px 16px;
  background: rgba(0,0,0,0.25);
  border-bottom: 1px solid var(--border);
}
.dot { width: 12px; height: 12px; border-radius: 50%; }
.dot-red    { background: #ff5f57; }
.dot-yellow { background: #ffbd2e; }
.dot-green  { background: #28c840; }
.code-title { margin-left: auto; font-size: 0.75rem; color: var(--text-muted); }
.code-body {
  padding: 20px;
  font-size: 0.82rem;
  line-height: 1.8;
  overflow-x: auto;
}
.c-kw  { color: #c792ea; }
.c-cls { color: var(--gold); }
.c-fn  { color: var(--blue-light); }
.c-var { color: #f07178; }
.c-str { color: #c3e88d; }
.c-num { color: #f78c6c; }
.c-comment { color: var(--text-dim); font-style: italic; }

/* ============================================
   SECTIONS
   ============================================ */
.section { padding: 100px 5%; }
.section-alt { background: var(--bg2); }

.container { max-width: 1100px; margin: 0 auto; }

.section-label {
  font-size: 0.82rem;
  color: var(--gold);
  letter-spacing: 0.1em;
  margin-bottom: 10px;
}
.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.5px;
  margin-bottom: 50px;
}
.section-title::after {
  content: '';
  display: block;
  width: 50px;
  height: 3px;
  background: var(--grad);
  border-radius: 2px;
  margin-top: 10px;
}

/* Fade-in animation */
.fade-in {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: none;
}

/* ============================================
   ABOUT
   ============================================ */
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: start; }

.about-text p {
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.75;
}
.about-text strong { color: var(--text); }

.about-links { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 24px; }
.about-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 0.87rem;
  color: var(--blue-light);
  padding: 6px 14px;
  border: 1px solid var(--border2);
  border-radius: 6px;
  transition: all 0.2s;
}
.about-link:hover { border-color: var(--gold); color: var(--gold); background: rgba(253,181,21,0.06); }

.about-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.mini-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  transition: transform 0.2s, box-shadow 0.2s;
}
.mini-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-glow); }
.mini-card-icon { font-size: 1.6rem; line-height: 1; }
.mini-card-title { font-weight: 600; font-size: 0.88rem; }
.mini-card-sub { font-size: 0.77rem; color: var(--text-muted); }

/* ============================================
   SKILLS
   ============================================ */
.skills-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }

.skill-category { padding: 28px; transition: transform 0.2s, box-shadow 0.2s; }
.skill-category:hover { transform: translateY(-4px); box-shadow: var(--shadow), var(--shadow-glow); }

.skill-cat-header { display: flex; align-items: center; gap: 10px; margin-bottom: 18px; }
.skill-cat-icon { font-size: 1.4rem; }
.skill-cat-title { font-size: 1rem; font-weight: 700; }

.skill-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 22px; }
.skill-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  padding: 4px 10px;
  border-radius: 4px;
  font-weight: 600;
}
.tag-blue   { background: rgba(0,87,168,0.2);  border: 1px solid rgba(59,130,246,0.4); color: #93c5fd; }
.tag-yellow { background: rgba(253,181,21,0.1); border: 1px solid rgba(253,181,21,0.35); color: var(--gold); }

.skill-bars { display: flex; flex-direction: column; gap: 12px; }
.skill-bar-item {}
.skill-bar-label { display: flex; justify-content: space-between; font-size: 0.8rem; color: var(--text-muted); margin-bottom: 5px; }
.skill-bar-label .mono { color: var(--gold); font-size: 0.72rem; }
.skill-bar-track { height: 5px; background: rgba(255,255,255,0.06); border-radius: 3px; overflow: hidden; }
.skill-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--blue-mid), var(--blue-light));
  border-radius: 3px;
  width: 0;
  transition: width 1.2s cubic-bezier(0.4,0,0.2,1);
}
.skill-bar-fill.bar-yellow {
  background: linear-gradient(90deg, #d97706, var(--gold));
}

/* ============================================
   EXPERIENCE / TIMELINE
   ============================================ */
.timeline { position: relative; padding-left: 30px; }
.timeline::before {
  content: '';
  position: absolute;
  left: 0;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(to bottom, var(--blue-mid), var(--gold), transparent);
}

.timeline-item { position: relative; margin-bottom: 36px; }
.timeline-dot {
  position: absolute;
  left: -38px;
  top: 22px;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--blue-mid);
  border: 3px solid var(--bg2);
  box-shadow: 0 0 0 2px var(--blue-light);
  z-index: 1;
}
.timeline-dot-alt {
  background: var(--gold);
  box-shadow: 0 0 0 2px var(--gold-light);
}

.timeline-content { padding: 24px 28px; transition: transform 0.2s; }
.timeline-content:hover { transform: translateX(4px); }

.timeline-header { display: flex; justify-content: space-between; align-items: flex-start; gap: 12px; margin-bottom: 14px; flex-wrap: wrap; }
.timeline-role { font-size: 1.05rem; font-weight: 700; }
.timeline-company { font-size: 0.87rem; color: var(--gold); margin-top: 3px; }
.timeline-date { font-size: 0.75rem; color: var(--text-muted); white-space: nowrap; padding: 3px 10px; border: 1px solid var(--border); border-radius: 100px; }

.timeline-bullets { padding-left: 18px; list-style: disc; color: var(--text-muted); font-size: 0.9rem; line-height: 1.7; margin-bottom: 16px; }
.timeline-bullets li { margin-bottom: 6px; }
.timeline-bullets strong { color: var(--text); }

.timeline-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tl-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  padding: 3px 10px;
  background: rgba(0,87,168,0.15);
  border: 1px solid var(--border2);
  border-radius: 4px;
  color: var(--blue-light);
}

/* ============================================
   PROJECTS
   ============================================ */
.projects-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }

.project-card {
  padding: 26px;
  transition: transform 0.25s, box-shadow 0.25s;
  display: flex;
  flex-direction: column;
}
.project-card:hover { transform: translateY(-6px); box-shadow: var(--shadow), 0 0 40px rgba(253,181,21,0.1); }

.project-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px; }
.project-icon { font-size: 2rem; }
.project-links { display: flex; gap: 10px; }
.project-link { color: var(--text-muted); transition: color 0.2s; }
.project-link:hover { color: var(--gold); }

.project-partner { font-size: 0.72rem; color: var(--gold); margin-bottom: 8px; letter-spacing: 0.05em; }
.project-title { font-size: 1.02rem; font-weight: 700; margin-bottom: 12px; line-height: 1.35; }
.project-desc { font-size: 0.87rem; color: var(--text-muted); line-height: 1.65; margin-bottom: 18px; flex: 1; }

.project-tags { display: flex; flex-wrap: wrap; gap: 7px; margin-top: auto; }
.p-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.68rem;
  padding: 3px 9px;
  background: rgba(253,181,21,0.08);
  border: 1px solid rgba(253,181,21,0.25);
  border-radius: 4px;
  color: var(--gold-light);
}

/* ============================================
   BLOGS
   ============================================ */
.blogs-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }

.blog-card {
  padding: 26px;
  display: flex;
  flex-direction: column;
  transition: transform 0.25s, box-shadow 0.25s;
}
.blog-card:hover { transform: translateY(-6px); box-shadow: var(--shadow), 0 0 40px rgba(253,181,21,0.1); }

.blog-date { font-size: 0.75rem; color: var(--gold); margin-bottom: 12px; }
.blog-title { font-size: 1.15rem; font-weight: 800; margin-bottom: 14px; line-height: 1.3; }
.blog-title a { transition: color 0.2s; }
.blog-title a:hover { color: var(--gold); }

.blog-desc { font-size: 0.87rem; color: var(--text-muted); line-height: 1.7; margin-bottom: 24px; }

.blog-footer { display: flex; justify-content: space-between; align-items: center; margin-top: auto; }
.blog-tag { font-size: 0.7rem; }
.blog-more { font-size: 0.82rem; font-weight: 600; color: var(--blue-light); transition: transform 0.2s; }
.blog-more:hover { color: var(--gold); transform: translateX(5px); }

/* ============================================
   EDUCATION
   ============================================ */
.edu-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }

.edu-card {
  display: flex;
  gap: 22px;
  padding: 28px;
  align-items: flex-start;
  transition: transform 0.2s;
}
.edu-card:hover { transform: translateY(-4px); }

.edu-logo {
  width: 58px; height: 58px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'JetBrains Mono', monospace;
  font-weight: 800;
  font-size: 0.95rem;
  flex-shrink: 0;
  letter-spacing: -1px;
}
.edu-logo-berkeley { background: linear-gradient(135deg, var(--blue), var(--blue-mid)); color: var(--gold); border: 1px solid rgba(253,181,21,0.3); }
.edu-logo-zju      { background: linear-gradient(135deg, #1a3a6c, #0d2244); color: #93c5fd; border: 1px solid rgba(59,130,246,0.3); }

.edu-body { flex: 1; }
.edu-header { display: flex; justify-content: space-between; align-items: flex-start; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.edu-degree { font-size: 1rem; font-weight: 700; }
.edu-school { font-size: 0.85rem; color: var(--text-muted); margin-top: 3px; }
.edu-date { font-size: 0.72rem; color: var(--text-dim); font-family: 'JetBrains Mono', monospace; white-space: nowrap; }

.edu-gpa { display: flex; align-items: center; gap: 8px; margin-bottom: 10px; }
.gpa-label { font-size: 0.72rem; color: var(--text-dim); letter-spacing: 0.08em; }
.gpa-value { font-size: 1.1rem; font-weight: 800; }

.edu-desc { font-size: 0.85rem; color: var(--text-muted); line-height: 1.6; margin-bottom: 14px; }

.edu-tags { display: flex; flex-wrap: wrap; gap: 7px; margin-bottom: 14px; }
.e-tag {
  font-size: 0.72rem;
  padding: 3px 10px;
  background: rgba(0,87,168,0.15);
  border: 1px solid var(--border2);
  border-radius: 4px;
  color: #93c5fd;
}

.edu-honors { display: flex; flex-direction: column; gap: 7px; }
.honor-badge {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.82rem;
  color: var(--text-muted);
  padding: 7px 12px;
  background: rgba(253,181,21,0.06);
  border: 1px solid rgba(253,181,21,0.15);
  border-radius: 6px;
}
.honor-icon { font-size: 1rem; }

/* ============================================
   CONTACT
   ============================================ */
.contact-wrapper { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; align-items: center; }

.contact-text p { color: var(--text-muted); line-height: 1.75; margin-bottom: 28px; font-size: 1rem; }
.contact-text strong { color: var(--text); }
.contact-btn { font-size: 1rem; padding: 14px 30px; }

.contact-links-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.contact-card {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 18px;
  transition: all 0.2s;
}
.contact-card:hover { transform: translateY(-3px); border-color: var(--gold); box-shadow: 0 8px 20px rgba(253,181,21,0.1); }

.contact-card-icon {
  width: 42px; height: 42px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.email-icon    { background: rgba(59,130,246,0.15); color: var(--blue-light); }
.github-icon   { background: rgba(255,255,255,0.08); color: var(--text); }
.location-icon { background: rgba(253,181,21,0.1); color: var(--gold); }
.resume-icon   { background: rgba(34,197,94,0.12); color: #4ade80; }

.contact-card-label { font-size: 0.72rem; color: var(--text-dim); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 3px; }
.contact-card-value { font-size: 0.82rem; color: var(--text); }

/* ============================================
   FOOTER
   ============================================ */
.footer {
  padding: 32px 5%;
  border-top: 1px solid var(--border);
  background: var(--bg);
}
.footer-inner { max-width: 1100px; margin: 0 auto; text-align: center; }
.footer-logo { font-size: 1.2rem; font-weight: 700; display: block; margin-bottom: 8px; background: var(--grad); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.footer-text { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 4px; }
.footer-sub { font-size: 0.75rem; color: var(--text-dim); }

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1024px) {
  .skills-grid { grid-template-columns: 1fr 1fr; }
  .projects-grid { grid-template-columns: 1fr 1fr; }
  .blogs-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 860px) {
  .hero { flex-direction: column; text-align: center; }
  .hero-content { max-width: 100%; }
  .hero-visual { width: 100%; max-width: 460px; margin: 0 auto; }
  .hero-badges, .hero-actions, .hero-stats { justify-content: center; }
  .about-grid { grid-template-columns: 1fr; }
  .edu-grid { grid-template-columns: 1fr; }
  .contact-wrapper { grid-template-columns: 1fr; }
  .contact-links-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 700px) {
  .nav-links { display: none; flex-direction: column; position: fixed; top: 64px; left: 0; right: 0; background: rgba(5,13,26,0.97); padding: 20px; gap: 8px; border-bottom: 1px solid var(--border); }
  .nav-links.open { display: flex; }
  .nav-hamburger { display: flex; }
  .skills-grid { grid-template-columns: 1fr; }
  .projects-grid { grid-template-columns: 1fr; }
  .blogs-grid { grid-template-columns: 1fr; }
  .about-cards { grid-template-columns: 1fr; }
  .section { padding: 70px 5%; }
  .hero { padding: 90px 5% 50px; }
  .timeline { padding-left: 20px; }
  .timeline::before { left: -4px; }
  .timeline-dot { left: -28px; }
}