/* ============================================================
   Dr. Mohamed Sirajudeen Yoosuf — Academic Portfolio
   Design tokens + base + components
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Crimson+Pro:wght@400;500;600;700&family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root{
  /* ---- color tokens (light) ---- */
  --color-ink:            #14213D;
  --color-ink-2:          #1E3A5F;
  --color-primary:        #1E3A5F;
  --color-on-primary:     #FFFFFF;
  --color-accent:         #B45309;
  --color-accent-2:       #C2760F;
  --color-on-accent:      #FFFFFF;
  --color-security:       #0E7490;
  --color-background:     #FBFAF7;
  --color-surface:        #FFFFFF;
  --color-surface-2:      #F3F1EA;
  --color-foreground:     #16213A;
  --color-muted:          #5B6478;
  --color-border:         #E4E0D6;
  --color-border-strong:  #D8D2C2;
  --color-ring:           #1E3A5F;
  --color-success:        #15803D;
  --color-danger:         #B91C1C;

  --shadow-sm: 0 1px 2px rgba(20,33,61,0.06);
  --shadow-md: 0 6px 20px -6px rgba(20,33,61,0.16);
  --shadow-lg: 0 20px 45px -18px rgba(20,33,61,0.28);

  --font-display: 'Crimson Pro', Georgia, 'Times New Roman', serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SFMono-Regular', Menlo, Consolas, monospace;

  --space-1: 4px;  --space-2: 8px;  --space-3: 12px; --space-4: 16px;
  --space-5: 24px; --space-6: 32px; --space-7: 48px; --space-8: 64px;
  --space-9: 96px; --space-10: 128px;

  --radius-sm: 6px; --radius-md: 12px; --radius-lg: 20px; --radius-full: 999px;

  --container-max: 1180px;
  --header-h: 76px;

  --dur-fast: 150ms; --dur-base: 250ms; --dur-slow: 450ms;
  --ease-out: cubic-bezier(.16,1,.3,1);
}

:root[data-theme="dark"]{
  --color-background:  #0E1522;
  --color-surface:     #141D2E;
  --color-surface-2:   #1B2438;
  --color-foreground:  #EDEEF2;
  --color-muted:       #9AA5BD;
  --color-border:      #263048;
  --color-border-strong: #33405E;
  --color-primary:     #7FA8D9;
  --color-on-primary:  #0E1522;
  --color-accent:      #E3A34B;
  --color-on-accent:   #16213A;
  --color-security:    #4DD4E8;
  --shadow-md: 0 6px 24px -6px rgba(0,0,0,0.45);
  --shadow-lg: 0 24px 55px -18px rgba(0,0,0,0.6);
}

/* Light is the standard, default appearance regardless of system preference.
   Dark mode applies only when explicitly switched on via the toggle (data-theme="dark"). */

*, *::before, *::after{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce){
  html{ scroll-behavior: auto; }
  *, *::before, *::after{ animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }
}

body{
  margin:0;
  background: var(--color-background);
  color: var(--color-foreground);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background-color var(--dur-base) var(--ease-out), color var(--dur-base) var(--ease-out);
}

img{ max-width:100%; display:block; }
a{ color: inherit; text-decoration:none; }
ul{ margin:0; padding:0; list-style:none; }
h1,h2,h3,h4{ font-family: var(--font-display); font-weight:600; line-height:1.15; margin:0 0 var(--space-4); color: var(--color-ink); }
:root[data-theme="dark"] h1, :root[data-theme="dark"] h2, :root[data-theme="dark"] h3, :root[data-theme="dark"] h4{ color: var(--color-foreground); }
p{ margin:0 0 var(--space-4); color: var(--color-foreground); }
strong{ font-weight:600; }
code, pre{ font-family: var(--font-mono); }

:focus-visible{ outline: 3px solid var(--color-security); outline-offset: 2px; border-radius: 4px; }

.container{ max-width: var(--container-max); margin-inline:auto; padding-inline: var(--space-5); }
@media (min-width:768px){ .container{ padding-inline: var(--space-7); } }

.eyebrow{
  display:inline-flex; align-items:center; gap:var(--space-2);
  font-family: var(--font-mono); font-size:12px; letter-spacing:.08em; text-transform:uppercase;
  color: var(--color-accent-2); font-weight:700; margin-bottom: var(--space-4);
  background: color-mix(in srgb, var(--color-accent) 12%, transparent);
  border: 1px solid color-mix(in srgb, var(--color-accent) 28%, transparent);
  padding: 7px 14px 7px 12px; border-radius: var(--radius-full);
}
.eyebrow::before{ content:""; width:7px; height:7px; border-radius:50%; background: var(--color-accent); display:inline-block; flex-shrink:0; }

h1{ font-size: clamp(2.1rem, 1.6rem + 2vw, 3.4rem); }
h2{ font-size: clamp(1.6rem, 1.4rem + 1vw, 2.2rem); }
h3{ font-size: 1.3rem; }
.section-head{ max-width: 700px; margin-bottom: var(--space-7); }
.section-head p{ color: var(--color-muted); font-size: 1.05rem; }
.text-muted{ color: var(--color-muted); }

section{ padding-block: var(--space-9); }
.section-tight{ padding-block: var(--space-8); }
.section-alt{ background: var(--color-surface-2); }

/* ---------------- buttons ---------------- */
.btn{
  display:inline-flex; align-items:center; gap:var(--space-2);
  font-family: var(--font-body); font-weight:600; font-size:.95rem;
  padding: 12px 22px; border-radius: var(--radius-full);
  border:1.5px solid transparent; cursor:pointer;
  transition: transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-base) var(--ease-out), background-color var(--dur-base), border-color var(--dur-base), color var(--dur-base);
  white-space:nowrap;
}
.btn:active{ transform: translateY(1px); }
.btn-primary{ background: var(--color-primary); color: var(--color-on-primary); box-shadow: var(--shadow-sm); }
.btn-primary:hover{ box-shadow: var(--shadow-md); }
.btn-accent{ background: var(--color-accent); color: var(--color-on-accent); box-shadow: var(--shadow-sm); }
.btn-accent:hover{ box-shadow: var(--shadow-md); }
.btn-ghost{ background: transparent; border-color: var(--color-border-strong); color: var(--color-foreground); }
.btn-ghost:hover{ border-color: var(--color-primary); }
.btn-sm{ padding: 8px 16px; font-size:.85rem; }
.btn[disabled], .btn.is-disabled{ opacity:.5; cursor:not-allowed; pointer-events:none; }
.btn svg{ width:16px; height:16px; flex-shrink:0; }

/* ---------------- header / nav ---------------- */
.site-header{
  position: sticky; top:0; z-index:100;
  background: var(--color-background);
  border-bottom: 1px solid var(--color-border);
  min-height: var(--header-h);
}
.site-header .container{ min-height: var(--header-h); display:flex; align-items:center; justify-content:space-between; gap: var(--space-4); padding-block: 10px; }
.brand{ display:flex; align-items:center; gap:10px; font-family: var(--font-display); font-weight:700; font-size:1.15rem; color: var(--color-ink); min-width:0; }
:root[data-theme="dark"] .brand{ color:var(--color-foreground); }
.brand-mark{
  width:38px; height:38px; border-radius: 10px;
  background: linear-gradient(155deg, var(--color-primary), var(--color-security));
  color:#fff; display:flex; align-items:center; justify-content:center;
  font-family: var(--font-mono); font-weight:700; font-size:15px; flex-shrink:0;
}
.brand-text{ min-width:0; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.brand small{ display:block; font-family: var(--font-body); font-weight:500; font-size:.68rem; color: var(--color-muted); letter-spacing:.03em; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
@media (max-width:480px){
  .brand{ font-size:.95rem; }
  .brand small{ display:none; }
}

.nav-desktop{ display:none; min-width:0; }
.nav-desktop ul{ display:flex; align-items:center; gap: var(--space-5); }
.nav-desktop a{
  font-size:.93rem; font-weight:600; color: var(--color-muted); white-space:nowrap;
  padding: 6px 2px; position:relative; transition: color var(--dur-fast);
}
.nav-desktop a::after{
  content:""; position:absolute; left:0; right:100%; bottom:-4px; height:2px; background: var(--color-accent);
  transition: right var(--dur-base) var(--ease-out);
}
.nav-desktop a:hover, .nav-desktop a.is-active{ color: var(--color-ink); }
:root[data-theme="dark"] .nav-desktop a:hover, :root[data-theme="dark"] .nav-desktop a.is-active{ color: var(--color-foreground); }
.nav-desktop a:hover::after, .nav-desktop a.is-active::after{ right:0; }
@media (min-width: 960px) and (max-width: 1180px){
  .nav-desktop ul{ gap: var(--space-4); }
  .nav-desktop a{ font-size:.85rem; }
}

.header-actions{ display:flex; align-items:center; gap: var(--space-3); }
.icon-btn{
  width:40px; height:40px; border-radius: var(--radius-full); display:flex; align-items:center; justify-content:center;
  border:1.5px solid var(--color-border-strong); background: var(--color-surface); color: var(--color-foreground); cursor:pointer;
  transition: border-color var(--dur-fast), transform var(--dur-fast);
}
.icon-btn:hover{ border-color: var(--color-primary); }
.icon-btn svg{ width:19px; height:19px; }
.icon-sun{ display:none; }
:root[data-theme="dark"] .icon-moon{ display: none; }
:root[data-theme="dark"] .icon-sun{ display: block; }
:root[data-theme="light"] .icon-moon{ display:block; }
:root[data-theme="light"] .icon-sun{ display:none; }

.nav-toggle{ display:flex; }
@media (min-width: 960px){
  .nav-desktop{ display:block; }
  .nav-toggle{ display:none; }
}

.mobile-nav{
  position: fixed; inset: var(--header-h) 0 0 0; background: var(--color-background);
  transform: translateX(100%); transition: transform var(--dur-base) var(--ease-out);
  z-index:99; overflow-y:auto;
}
.mobile-nav.is-open{ transform: translateX(0); }
.mobile-nav ul{ display:flex; flex-direction:column; padding: var(--space-6) var(--space-5); gap: var(--space-2); }
.mobile-nav a{ display:block; padding: 16px 4px; font-size:1.25rem; font-family:var(--font-display); font-weight:600; border-bottom:1px solid var(--color-border); }
@media (min-width:960px){ .mobile-nav{ display:none; } }

/* ---------------- hero ---------------- */
.hero{ padding-block: var(--space-8) var(--space-9); position:relative; overflow:hidden; }
.hero::before{
  content:""; position:absolute; inset:-20% -10% auto -10%; height:560px; z-index:-1;
  background:
    radial-gradient(600px 320px at 15% 10%, color-mix(in srgb, var(--color-security) 14%, transparent), transparent 70%),
    radial-gradient(500px 300px at 90% 0%, color-mix(in srgb, var(--color-accent) 16%, transparent), transparent 70%),
    linear-gradient(color-mix(in srgb, var(--color-ink) 6%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--color-ink) 6%, transparent) 1px, transparent 1px);
  background-size: auto, auto, 36px 36px, 36px 36px;
  mask-image: radial-gradient(ellipse 900px 480px at 30% 15%, black 0%, transparent 75%);
}
.hero-grid{ display:grid; gap: var(--space-8); align-items:center; }
@media (min-width: 900px){ .hero-grid{ grid-template-columns: 1.15fr .85fr; gap: var(--space-9); } }
.hero-copy h1{ margin-bottom: var(--space-3); }
.hero-role{ font-size: 1.15rem; color: var(--color-primary); font-weight:600; margin-bottom: var(--space-4); }
:root[data-theme="dark"] .hero-role{ color: var(--color-security); }
.hero-copy p.lede{ font-size: 1.1rem; color: var(--color-muted); max-width: 54ch; }
.hero-actions{ display:flex; flex-wrap:wrap; gap: var(--space-3); margin-top: var(--space-6); }
.hero-social{ display:flex; flex-wrap:wrap; gap: var(--space-3); margin-top: var(--space-6); }

.hero-portrait{ position:relative; justify-self:center; }
.portrait-frame{
  width: min(320px, 72vw); aspect-ratio: 1/1.08; border-radius: var(--radius-lg);
  overflow:hidden; position:relative; box-shadow: var(--shadow-lg);
  border: 1px solid var(--color-border);
}
.portrait-frame img{ width:100%; height:100%; object-fit:cover; }
.portrait-badge{
  position:absolute; bottom:-18px; left:-18px; background: var(--color-surface);
  border:1px solid var(--color-border); border-radius: var(--radius-md); box-shadow: var(--shadow-md);
  padding: 12px 16px; display:flex; align-items:center; gap:10px; max-width:220px;
}
.portrait-badge .dot{ width:10px; height:10px; border-radius:50%; background: var(--color-success); flex-shrink:0; box-shadow:0 0 0 4px color-mix(in srgb, var(--color-success) 20%, transparent); }
.portrait-badge span{ font-size:.8rem; font-weight:600; color: var(--color-foreground); }

/* ---------------- stats ---------------- */
.stat-strip{ display:grid; grid-template-columns: repeat(2,1fr); gap: var(--space-5); border-top:1px solid var(--color-border); border-bottom:1px solid var(--color-border); padding-block: var(--space-7); }
@media (min-width:700px){ .stat-strip{ grid-template-columns: repeat(4,1fr); } .stat-strip-3{ grid-template-columns: repeat(3,1fr); max-width:760px; margin-inline:auto; } }
.stat-item{ text-align:center; }
.stat-icon{
  width:44px; height:44px; margin:0 auto 14px; border-radius: var(--radius-md);
  display:flex; align-items:center; justify-content:center;
  background: color-mix(in srgb, var(--color-primary) 9%, transparent); color: var(--color-primary);
}
:root[data-theme="dark"] .stat-icon{ background: color-mix(in srgb, var(--color-security) 14%, transparent); color: var(--color-security); }
.stat-icon svg{ width:22px; height:22px; }
.stat-num{ font-family: var(--font-display); font-weight:700; font-size: clamp(1.8rem,1.5rem + 1vw, 2.6rem); color: var(--color-ink); display:block; }
:root[data-theme="dark"] .stat-num{ color: var(--color-foreground); }
.stat-label{ font-size:.85rem; color: var(--color-muted); margin-top:4px; }

/* ---------------- cards / grid ---------------- */
.grid{ display:grid; gap: var(--space-5); }
.grid-2{ grid-template-columns: repeat(1,1fr); }
.grid-3{ grid-template-columns: repeat(1,1fr); }
.grid-4{ grid-template-columns: repeat(1,1fr); }
@media (min-width:640px){ .grid-2{ grid-template-columns: repeat(2,1fr); } .grid-4{ grid-template-columns: repeat(2,1fr); } }
@media (min-width:960px){ .grid-3{ grid-template-columns: repeat(3,1fr); } .grid-4{ grid-template-columns: repeat(4,1fr); } }

.card{
  background: var(--color-surface); border:1px solid var(--color-border); border-radius: var(--radius-lg);
  padding: var(--space-6); box-shadow: var(--shadow-sm);
  transition: transform var(--dur-base) var(--ease-out), box-shadow var(--dur-base) var(--ease-out), border-color var(--dur-base);
}
.card:hover{ transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--color-border-strong); }
.card-icon{
  width:48px; height:48px; border-radius: var(--radius-md); display:flex; align-items:center; justify-content:center;
  background: color-mix(in srgb, var(--color-primary) 10%, transparent); color: var(--color-primary); margin-bottom: var(--space-4);
}
:root[data-theme="dark"] .card-icon{ color: var(--color-security); background: color-mix(in srgb, var(--color-security) 14%, transparent); }
.card-icon svg{ width:24px; height:24px; }
.card h3{ margin-bottom: var(--space-2); font-size:1.15rem; }
.card p{ color: var(--color-muted); font-size:.95rem; margin-bottom: var(--space-3); }
.card-link{ font-weight:600; font-size:.88rem; color: var(--color-accent); display:inline-flex; align-items:center; gap:6px; }
.card-link svg{ width:14px; height:14px; transition: transform var(--dur-fast); }
.card-link:hover svg{ transform: translateX(3px); }

/* tag / pill */
.tag-row{ display:flex; flex-wrap:wrap; gap: var(--space-2); }
.tag{
  font-size:.82rem; font-weight:600; padding: 7px 14px; border-radius: var(--radius-full);
  background: var(--color-surface-2); color: var(--color-foreground); border:1px solid var(--color-border);
}
.tag.tag-accent{ background: color-mix(in srgb, var(--color-accent) 14%, transparent); color: var(--color-accent-2); border-color: transparent; }
.tag.tag-security{ background: color-mix(in srgb, var(--color-security) 14%, transparent); color: var(--color-security); border-color: transparent; }
.badge{ display:inline-flex; align-items:center; gap:6px; font-size:.72rem; font-weight:700; text-transform:uppercase; letter-spacing:.04em; padding:5px 11px; border-radius: var(--radius-full); }
.badge-live{ background: color-mix(in srgb, var(--color-success) 16%, transparent); color: var(--color-success); }
.badge-soon{ background: var(--color-surface-2); color: var(--color-muted); border:1px dashed var(--color-border-strong); }

/* ---------------- social icons row ---------------- */
.social-row{ display:flex; flex-wrap:wrap; gap: var(--space-3); }
.social-chip{
  display:flex; align-items:center; gap:8px; padding: 10px 16px; border-radius: var(--radius-full);
  border:1.5px solid var(--color-border-strong); font-size:.85rem; font-weight:600; background: var(--color-surface);
  transition: border-color var(--dur-fast), transform var(--dur-fast), background var(--dur-fast);
}
.social-chip svg{ width:17px; height:17px; }
.social-chip:hover{ border-color: var(--color-primary); transform: translateY(-2px); }
.social-chip.is-pending{ opacity:.55; cursor:default; }
.social-chip.is-pending:hover{ transform:none; border-color: var(--color-border-strong); }

/* ---------------- timeline ---------------- */
.timeline{ position:relative; padding-left: 28px; border-left: 2px solid var(--color-border); }
.timeline-item{ position:relative; padding-bottom: var(--space-6); }
.timeline-item:last-child{ padding-bottom:0; }
.timeline-item::before{
  content:""; position:absolute; left:-34px; top:4px; width:12px; height:12px; border-radius:50%;
  background: var(--color-surface); border:3px solid var(--color-primary);
}
.timeline-date{ font-family: var(--font-mono); font-size:.78rem; color: var(--color-accent); font-weight:600; letter-spacing:.03em; margin-bottom:4px; display:block; }
.timeline-item h4{ margin-bottom:2px; font-size:1.05rem; }
.timeline-item .org{ color: var(--color-muted); font-size:.9rem; margin-bottom:6px; display:block; }

/* ---------------- tabs ---------------- */
.tabs{ }
.tab-list{ display:flex; flex-wrap:wrap; gap: var(--space-2); margin-bottom: var(--space-6); border-bottom:1px solid var(--color-border); padding-bottom: var(--space-4); }
.tab-btn{
  font-family: var(--font-body); font-weight:600; font-size:.88rem; padding: 9px 18px; border-radius: var(--radius-full);
  border:1.5px solid var(--color-border-strong); background: var(--color-surface); color: var(--color-muted); cursor:pointer;
  transition: all var(--dur-fast);
}
.tab-btn:hover{ border-color: var(--color-primary); color: var(--color-foreground); }
.tab-btn.is-active{ background: var(--color-primary); color: var(--color-on-primary); border-color: var(--color-primary); }
.tab-panel{ display:none; }
.tab-panel.is-active{ display:block; animation: fadeIn var(--dur-base) var(--ease-out); }
@keyframes fadeIn{ from{ opacity:0; transform: translateY(6px);} to{ opacity:1; transform:none; } }

/* ---------------- publication list ---------------- */
.pub-list{ display:flex; flex-direction:column; gap: var(--space-4); }
.pub-item{
  display:flex; gap: var(--space-4); padding: var(--space-5); background: var(--color-surface);
  border:1px solid var(--color-border); border-radius: var(--radius-md); align-items:flex-start;
}
.pub-index{ font-family: var(--font-mono); color: var(--color-accent); font-weight:700; font-size:.85rem; flex-shrink:0; width:28px; padding-top:2px; }
.pub-body h4{ font-size:1rem; margin-bottom:4px; line-height:1.4; }
.pub-meta{ font-size:.83rem; color: var(--color-muted); margin-bottom:6px; }
.pub-venue{ font-style:italic; }
.pub-tags{ display:flex; flex-wrap:wrap; gap:6px; margin-top:8px; }

/* ---------------- table ---------------- */
.table-wrap{ overflow-x:auto; border:1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-surface); }
table{ width:100%; border-collapse:collapse; font-size:.9rem; min-width:560px; }
thead th{ text-align:left; background: var(--color-surface-2); font-family:var(--font-mono); font-size:.72rem; text-transform:uppercase; letter-spacing:.05em; color: var(--color-muted); padding: 12px 16px; border-bottom:1px solid var(--color-border); }
tbody td{ padding: 14px 16px; border-bottom:1px solid var(--color-border); vertical-align:top; color: var(--color-foreground); }
tbody tr:last-child td{ border-bottom:none; }
tbody tr:hover{ background: color-mix(in srgb, var(--color-primary) 4%, transparent); }

/* ---------------- accordion (course lab list) ---------------- */
.accordion-item{ border:1px solid var(--color-border); border-radius: var(--radius-md); margin-bottom: var(--space-3); overflow:hidden; background: var(--color-surface); }
.accordion-trigger{
  width:100%; display:flex; align-items:center; justify-content:space-between; gap: var(--space-3);
  padding: var(--space-5); background:none; border:none; cursor:pointer; font-family: var(--font-body);
  font-weight:600; font-size:1rem; color: var(--color-foreground); text-align:left;
}
.accordion-trigger svg{ width:18px; height:18px; flex-shrink:0; transition: transform var(--dur-base) var(--ease-out); color: var(--color-muted); }
.accordion-item.is-open .accordion-trigger svg{ transform: rotate(180deg); }
.accordion-panel{ max-height:0; overflow:hidden; transition: max-height var(--dur-slow) var(--ease-out); }
.accordion-panel-inner{ padding: 0 var(--space-5) var(--space-5); color: var(--color-muted); }
.accordion-panel-inner ul{ display:flex; flex-direction:column; gap:8px; margin-top:8px; }
.accordion-panel-inner li{ position:relative; padding-left:20px; }
.accordion-panel-inner li::before{ content:"→"; position:absolute; left:0; color: var(--color-accent); font-weight:700; }

/* ---------------- footer ---------------- */
.site-footer{ background: var(--color-ink); color: #C9D2E3; padding-block: var(--space-8) var(--space-6); }
:root[data-theme="dark"] .site-footer{ background:#0A0F1A; }
.site-footer a{ color:#C9D2E3; }
.site-footer h4{ color:#fff; font-size:1rem; margin-bottom: var(--space-3); }
.footer-grid{ display:grid; gap: var(--space-6); }
@media (min-width:768px){ .footer-grid{ grid-template-columns: 1.4fr 1fr 1fr; } }
.footer-grid ul{ display:flex; flex-direction:column; gap:10px; font-size:.9rem; }
.footer-grid ul a:hover{ color:#fff; }
.footer-bottom{ margin-top: var(--space-7); padding-top: var(--space-5); border-top:1px solid rgba(255,255,255,.12); display:flex; flex-wrap:wrap; gap: var(--space-3); justify-content:space-between; font-size:.8rem; color:#8C97AE; }

/* ---------------- page hero (inner pages) ---------------- */
.page-hero{ padding-block: var(--space-8) var(--space-7); border-bottom:1px solid var(--color-border); }
.breadcrumb{ display:flex; align-items:center; gap:8px; font-size:.85rem; color: var(--color-muted); margin-bottom: var(--space-4); }
.breadcrumb a:hover{ color: var(--color-primary); }

/* course security hero */
.course-hero{
  background: linear-gradient(165deg, #0A1628, #10233A 60%, #0E1522);
  color:#EAF1FB; position:relative; overflow:hidden;
}
.course-hero::before{
  content:""; position:absolute; inset:0; opacity:.35; pointer-events:none;
  background-image: linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 34px 34px;
  mask-image: radial-gradient(ellipse at 30% 20%, black 0%, transparent 70%);
}
.course-hero .eyebrow{ color:#4DD4E8; background: rgba(77,212,232,0.12); border-color: rgba(77,212,232,0.35); }
.course-hero .eyebrow::before{ background:#4DD4E8; }
.course-hero h1{ color:#fff; }
.course-hero p.lede{ color:#A9BAD4; }
.course-hero .btn-ghost{ color:#fff; border-color: rgba(255,255,255,.3); }
.course-hero .btn-ghost:hover{ border-color:#4DD4E8; }
.course-meta-row{ display:flex; flex-wrap:wrap; gap: var(--space-3); margin-top: var(--space-5); }
.course-meta-chip{
  display:flex; align-items:center; gap:8px; padding:9px 16px; border-radius: var(--radius-full);
  background: rgba(255,255,255,.06); border:1px solid rgba(255,255,255,.14); font-size:.82rem; color:#DCE6F5;
}
.course-meta-chip svg{ width:15px; height:15px; color:#4DD4E8; }

.coming-soon-card{ border:1.5px dashed var(--color-border-strong); background: transparent; box-shadow:none; }
.coming-soon-card:hover{ transform:none; box-shadow:none; }

.callout{
  border-left: 4px solid var(--color-accent); background: color-mix(in srgb, var(--color-accent) 8%, var(--color-surface));
  padding: var(--space-5); border-radius: var(--radius-md); font-size:.95rem; color: var(--color-foreground);
}
.callout strong{ color: var(--color-accent-2); }

/* reveal on scroll */
.reveal{ opacity:0; transform: translateY(18px); transition: opacity .6s var(--ease-out), transform .6s var(--ease-out); }
.reveal.is-visible{ opacity:1; transform:none; }
@media (prefers-reduced-motion: reduce){ .reveal{ opacity:1; transform:none; } }

.back-to-top{
  position: fixed; right: var(--space-5); bottom: var(--space-5); width:46px; height:46px; border-radius:50%;
  background: var(--color-primary); color: var(--color-on-primary); display:flex; align-items:center; justify-content:center;
  box-shadow: var(--shadow-md); opacity:0; pointer-events:none; transform: translateY(10px);
  transition: opacity var(--dur-base), transform var(--dur-base); z-index:80; border:none; cursor:pointer;
}
.back-to-top.is-visible{ opacity:1; pointer-events:auto; transform:none; }
.back-to-top svg{ width:20px; height:20px; }

.two-col{ display:grid; gap: var(--space-7); }
@media (min-width:900px){ .two-col{ grid-template-columns: 1fr 1fr; } }
.two-col.lopsided{ }
@media (min-width:900px){ .two-col.lopsided{ grid-template-columns: 1.3fr .7fr; } }

.list-check{ display:flex; flex-direction:column; gap: 14px; }
.list-check li{ display:flex; gap:12px; align-items:flex-start; font-size:.96rem; }
.list-check svg{ width:20px; height:20px; color: var(--color-success); flex-shrink:0; margin-top:2px; }

hr.rule{ border:none; border-top:1px solid var(--color-border); margin: var(--space-7) 0; }

.skip-link{
  position:absolute; left:-999px; top:auto; background: var(--color-primary); color:#fff; padding:12px 20px; z-index:200; border-radius:0 0 8px 0;
}
.skip-link:focus{ left:0; top:0; }