/* TechLife Frontiers – Warm Design Shared Stylesheet */
@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,400;0,9..144,600;0,9..144,700;1,9..144,400;1,9..144,600&family=Outfit:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

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

:root {
  --bg:           #fefcf7;
  --bg-2:         #f7f2e8;
  --bg-3:         #ede5d4;
  --text:         #1c1714;
  --text-2:       #5c4f42;
  --text-3:       #9b8c7d;
  --accent:       #d97706;
  --accent-dark:  #b45309;
  --accent-light: #fffbeb;
  --accent-mid:   #fde68a;
  --teal:         #0f766e;
  --teal-light:   #f0fdfa;
  --coral:        #dc4e3a;
  --coral-light:  #fff5f3;
  --purple:       #7c3aed;
  --purple-light: #f5f3ff;
  --green:        #1a7a3e;
  --green-light:  #f0fdf4;
  --sky:          #0369a1;
  --sky-light:    #f0f9ff;
  --border:       #e8ddd0;
  --shadow-sm:    0 1px 3px rgba(0,0,0,0.06);
  --shadow-md:    0 4px 20px rgba(0,0,0,0.09);
  --shadow-lg:    0 12px 40px rgba(0,0,0,0.13);
  --radius:       12px;
  --radius-lg:    18px;
  --font-head:    'Fraunces', serif;
  --font-body:    'Outfit', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;
}

html { scroll-behavior: smooth; }
body { font-family: var(--font-body); background: var(--bg); color: var(--text); overflow-x: hidden; }
.container { max-width: 1140px; margin: 0 auto; padding: 0 32px; }

/* ── NAV ── */
nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(254,252,247,0.95);
  backdrop-filter: blur(20px) saturate(140%);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1140px; margin: 0 auto; padding: 0 32px;
  display: flex; align-items: center; justify-content: space-between;
  height: 62px;
}
.logo { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); }
.logo-mark {
  width: 36px; height: 36px; border-radius: 10px;
  background: var(--accent); display: flex; align-items: center;
  justify-content: center; font-size: 1.1rem;
}
.logo-text { font-family: var(--font-head); font-size: 1rem; font-weight: 700; line-height: 1.1; }
.logo-text span { display: block; font-size: 0.6rem; font-family: var(--font-body); font-weight: 400; color: var(--text-3); letter-spacing: 0.01em; }

.nav-links { display: flex; align-items: center; gap: 2px; list-style: none; }
.nav-links a {
  font-size: 0.875rem; font-weight: 500; color: var(--text-2);
  text-decoration: none; padding: 6px 13px; border-radius: 8px;
  transition: color 0.15s, background 0.15s;
}
.nav-links a:hover { color: var(--text); background: var(--bg-2); }
.nav-cta {
  background: var(--accent) !important; color: #fff !important;
  font-weight: 600 !important; padding: 8px 18px !important;
}
.nav-cta:hover { background: var(--accent-dark) !important; }

.nav-back {
  display: flex; align-items: center; gap: 6px;
  font-size: 0.85rem; font-weight: 500; color: var(--text-2);
  text-decoration: none; padding: 7px 14px;
  border-radius: 8px; border: 1px solid var(--border);
  transition: all 0.15s;
}
.nav-back:hover { color: var(--text); background: var(--bg-2); }

/* ── FOOTER ── */
footer { background: var(--text); padding: 56px 0 28px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 48px; margin-bottom: 40px; }
.footer-logo { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.footer-logo .logo-mark { background: var(--accent); }
.footer-logo .logo-text { color: #fff; }
.footer-logo .logo-text span { color: rgba(255,255,255,0.3); }
.footer-brand p { font-size: 0.84rem; color: rgba(255,255,255,0.4); line-height: 1.74; max-width: 240px; }
.footer-col h5 { font-family: var(--font-head); font-size: 0.9rem; font-weight: 700; color: rgba(255,255,255,0.82); margin-bottom: 14px; }
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 9px; }
.footer-col a { font-size: 0.82rem; color: rgba(255,255,255,0.36); text-decoration: none; transition: color 0.15s; }
.footer-col a:hover { color: rgba(255,255,255,0.78); }
.footer-bottom {
  display: flex; align-items: center; justify-content: space-between;
  padding-top: 24px; border-top: 1px solid rgba(255,255,255,0.08);
  font-size: 0.77rem; color: rgba(255,255,255,0.24);
}

/* ── BUTTONS ── */
.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--accent); color: #fff;
  font-family: var(--font-body); font-weight: 600; font-size: 0.94rem;
  padding: 13px 26px; border-radius: 10px; text-decoration: none; border: none; cursor: pointer;
  transition: background 0.15s, transform 0.15s; white-space: nowrap;
}
.btn-primary:hover { background: var(--accent-dark); transform: translateY(-1px); }
.btn-secondary {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--bg); color: var(--text-2);
  font-family: var(--font-body); font-weight: 500; font-size: 0.94rem;
  padding: 12px 22px; border-radius: 10px; text-decoration: none;
  border: 1px solid var(--border); cursor: pointer;
  transition: background 0.15s, color 0.15s; white-space: nowrap;
}
.btn-secondary:hover { background: var(--bg-2); color: var(--text); }

/* ── SECTION HEADER ── */
.s-eyebrow {
  font-family: var(--font-mono); font-size: 0.68rem;
  color: var(--accent); letter-spacing: 0.14em;
  text-transform: uppercase; display: block; margin-bottom: 10px;
}
.s-title {
  font-family: var(--font-head); font-size: clamp(1.9rem, 3vw, 2.8rem);
  font-weight: 700; letter-spacing: -0.02em;
  color: var(--text); line-height: 1.1; margin-bottom: 12px;
}
.s-title em { font-style: italic; color: var(--accent); }
.s-sub { font-size: 1rem; color: var(--text-2); line-height: 1.74; max-width: 500px; }
.s-header { margin-bottom: 52px; }
.s-header.centered { text-align: center; }
.s-header.centered .s-sub { margin: 0 auto; }

/* ── LEVEL BADGES ── */
.lvl { font-size: 0.7rem; font-weight: 600; padding: 3px 9px; border-radius: 5px; white-space: nowrap; }
.lvl-beginner { background: var(--teal-light); color: var(--teal); }
.lvl-easy     { background: var(--accent-light); color: var(--accent); }
.lvl-anyone   { background: var(--bg-2); color: var(--text-2); border: 1px solid var(--border); }

/* ── TOOL CHIPS ── */
.tool-chip {
  display: inline-flex; align-items: center;
  background: var(--accent-light); color: var(--accent);
  border: 1px solid var(--accent-mid); border-radius: 6px;
  padding: 2px 9px; font-size: 0.73rem; font-weight: 600;
  font-family: var(--font-mono); margin: 2px; text-decoration: none;
  transition: opacity 0.15s;
}
.tool-chip:hover { opacity: 0.8; }
.tool-chip.teal   { background: var(--teal-light);   color: var(--teal);   border-color: rgba(15,118,110,0.3); }
.tool-chip.purple { background: var(--purple-light);  color: var(--purple); border-color: rgba(124,58,237,0.3); }
.tool-chip.green  { background: var(--green-light);   color: var(--green);  border-color: rgba(26,122,62,0.3); }
.tool-chip.sky    { background: var(--sky-light);     color: var(--sky);    border-color: rgba(3,105,161,0.3); }

/* ── TRY-IT BOX ── */
.try-box {
  background: var(--accent-light); border: 2px solid var(--accent-mid);
  border-radius: var(--radius); padding: 20px 22px; margin-top: 24px;
}
.try-box h4 { font-family: var(--font-head); font-size: 1rem; font-weight: 700; color: var(--accent); margin-bottom: 8px; }
.try-box p  { font-size: 0.875rem; color: var(--text-2); line-height: 1.65; margin: 0; }
.try-box.teal   { background: var(--teal-light);   border-color: rgba(15,118,110,0.3); }
.try-box.teal h4 { color: var(--teal); }
.try-box.coral  { background: var(--coral-light);  border-color: rgba(220,78,58,0.25); }
.try-box.coral h4 { color: var(--coral); }
.try-box.purple { background: var(--purple-light); border-color: rgba(124,58,237,0.25); }
.try-box.purple h4 { color: var(--purple); }
.try-box.green  { background: var(--green-light);  border-color: rgba(26,122,62,0.25); }
.try-box.green h4 { color: var(--green); }
.try-box.sky    { background: var(--sky-light);    border-color: rgba(3,105,161,0.25); }
.try-box.sky h4 { color: var(--sky); }

/* ── YOUTUBE THUMBNAIL ── */
.yt-thumb { display: block; position: relative; border-radius: 10px; overflow: hidden; margin: 20px 0; text-decoration: none; }
.yt-thumb img { width: 100%; display: block; aspect-ratio: 16/9; object-fit: cover; }
.yt-thumb .yt-overlay { position: absolute; inset: 0; background: rgba(0,0,0,0.3); display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px; transition: background 0.2s; }
.yt-thumb:hover .yt-overlay { background: rgba(0,0,0,0.5); }
.yt-thumb .yt-play { width: 60px; height: 60px; background: #ff0000; border-radius: 50%; display: flex; align-items: center; justify-content: center; color: #fff; font-size: 1.4rem; padding-left: 4px; box-shadow: 0 4px 16px rgba(0,0,0,0.4); transition: transform 0.15s; }
.yt-thumb:hover .yt-play { transform: scale(1.1); }
.yt-thumb .yt-label { color: #fff; font-size: 0.82rem; font-weight: 600; letter-spacing: 0.03em; text-shadow: 0 1px 4px rgba(0,0,0,0.6); }

/* ── REVEAL ── */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity 0.6s ease, transform 0.6s ease; }
.reveal.visible { opacity: 1; transform: none; }

/* ── LESSON PAGE ── */
.lesson-page-header {
  padding: 44px 0 0;
  border-bottom: 1px solid var(--border);
}
.lesson-page-header.amber  { background: linear-gradient(175deg, #fffbeb 0%, var(--bg) 100%); }
.lesson-page-header.teal   { background: linear-gradient(175deg, #f0fdfa 0%, var(--bg) 100%); }
.lesson-page-header.coral  { background: linear-gradient(175deg, #fff5f3 0%, var(--bg) 100%); }
.lesson-page-header.purple { background: linear-gradient(175deg, #f5f3ff 0%, var(--bg) 100%); }
.lesson-page-header.green  { background: linear-gradient(175deg, #f0fdf4 0%, var(--bg) 100%); }
.lesson-page-header.sky    { background: linear-gradient(175deg, #f0f9ff 0%, var(--bg) 100%); }

.lesson-breadcrumb { font-size: 0.8rem; color: var(--text-3); margin-bottom: 12px; }
.lesson-breadcrumb a { color: var(--text-2); text-decoration: none; }
.lesson-breadcrumb a:hover { color: var(--accent); }
.lesson-breadcrumb span { margin: 0 6px; opacity: 0.5; }

.lesson-number-badge {
  font-family: var(--font-mono); font-size: 0.68rem; font-weight: 500;
  color: var(--text-3); margin-bottom: 8px; display: block; letter-spacing: 0.08em;
}
.lesson-page-header h1 {
  font-family: var(--font-head); font-size: clamp(1.75rem, 4vw, 2.6rem);
  font-weight: 700; line-height: 1.12; color: var(--text);
  letter-spacing: -0.02em; margin-bottom: 18px; max-width: 740px;
}
.lesson-meta { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; margin-bottom: 32px; }
.lesson-meta-item { font-size: 0.8rem; color: var(--text-2); display: flex; align-items: center; gap: 4px; }
.format-badge {
  font-size: 0.7rem; font-weight: 600; padding: 3px 9px; border-radius: 5px;
  background: var(--bg-2); color: var(--text-2); border: 1px solid var(--border);
}

.lesson-body { padding: 52px 0 60px; }
.lesson-article {
  max-width: 720px; margin: 0 auto;
  font-size: 1.01rem; color: var(--text-2); line-height: 1.82;
}
.lesson-article p { margin-bottom: 16px; }
.lesson-article h3 {
  font-family: var(--font-head); font-size: 1.25rem; font-weight: 700;
  color: var(--text); margin: 32px 0 10px; letter-spacing: -0.015em; line-height: 1.2;
}
.lesson-article ul, .lesson-article ol { padding-left: 20px; margin-bottom: 16px; }
.lesson-article li { margin-bottom: 6px; }
.lesson-article strong { color: var(--text); font-weight: 600; }
.lesson-article em { font-style: italic; }
.lesson-article .highlight-box {
  background: var(--bg-2); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 18px 20px; margin: 20px 0;
  font-size: 0.9rem;
}

.lesson-nav-bottom {
  max-width: 720px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 24px 0 56px; border-top: 1px solid var(--border);
  gap: 12px; flex-wrap: wrap;
}
.lesson-nav-bottom a {
  font-size: 0.85rem; font-weight: 500; color: var(--text-2);
  text-decoration: none; padding: 9px 16px; border-radius: 8px;
  border: 1px solid var(--border); background: var(--bg);
  transition: all 0.15s; display: flex; align-items: center; gap: 6px;
}
.lesson-nav-bottom a:hover { background: var(--bg-2); color: var(--text); }
.lesson-nav-bottom .nav-all { background: var(--bg-2); font-weight: 600; }

/* ── LESSONS DIRECTORY ── */
.lessons-dir-header {
  background: var(--text);
  padding: 56px 0 0; position: relative; overflow: hidden;
}
.lessons-dir-header::before {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse 50% 70% at 85% 50%, rgba(217,119,6,0.14) 0%, transparent 60%);
  pointer-events: none;
}
.lessons-dir-header .container { position: relative; z-index: 1; }
.lessons-dir-header h1 {
  font-family: var(--font-head); font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700; color: #fff; letter-spacing: -0.03em; margin-bottom: 10px; line-height: 1.1;
}
.lessons-dir-header h1 em { font-style: italic; color: #fcd34d; }
.lessons-dir-header p { font-size: 1rem; color: rgba(255,255,255,0.52); max-width: 500px; line-height: 1.7; margin-bottom: 36px; }

.cat-tabs { display: flex; gap: 4px; overflow-x: auto; scrollbar-width: none; }
.cat-tabs::-webkit-scrollbar { display: none; }
.tab-btn {
  display: flex; align-items: center; gap: 8px;
  padding: 11px 20px; border: none; background: transparent; cursor: pointer;
  font-family: var(--font-body); font-size: 0.875rem; font-weight: 500;
  color: rgba(255,255,255,0.5); border-radius: 10px 10px 0 0;
  border: 1px solid transparent; border-bottom: none;
  white-space: nowrap; transition: all 0.15s; position: relative; bottom: -1px;
}
.tab-btn:hover { color: rgba(255,255,255,0.85); background: rgba(255,255,255,0.07); }
.tab-btn.active {
  color: var(--text); background: var(--bg);
  border-color: var(--border); border-bottom-color: var(--bg); font-weight: 600;
}
.tab-icon { font-size: 1rem; }
.tab-count {
  font-family: var(--font-mono); font-size: 0.62rem;
  background: rgba(217,119,6,0.3); color: #fcd34d; padding: 2px 7px; border-radius: 10px;
}
.tab-btn.active .tab-count { background: var(--accent); color: #fff; }

.tab-panel { display: none; padding: 48px 0 80px; }
.tab-panel.active { display: block; }

/* Lesson card grid */
.lesson-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }

.lesson-card {
  background: var(--bg); border: 1px solid var(--border);
  border-radius: var(--radius-lg); overflow: hidden;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none; color: var(--text); display: flex; flex-direction: column;
}
.lesson-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }

.lesson-card-top {
  height: 90px; display: flex; align-items: center; justify-content: center;
  font-size: 2.4rem; position: relative;
}
.lesson-card-top.amber  { background: linear-gradient(135deg, #fffbeb, #fef3c7); }
.lesson-card-top.teal   { background: linear-gradient(135deg, #f0fdfa, #ccfbf1); }
.lesson-card-top.coral  { background: linear-gradient(135deg, #fff5f3, #fce7e4); }
.lesson-card-top.purple { background: linear-gradient(135deg, #f5f3ff, #ede9fe); }
.lesson-card-top.green  { background: linear-gradient(135deg, #f0fdf4, #dcfce7); }
.lesson-card-top.sky    { background: linear-gradient(135deg, #f0f9ff, #e0f2fe); }

.card-num {
  position: absolute; top: 10px; left: 12px;
  font-family: var(--font-mono); font-size: 0.62rem; font-weight: 500;
  color: var(--text-3); letter-spacing: 0.06em;
}
.format-tag {
  position: absolute; top: 10px; right: 12px;
  font-size: 0.62rem; font-weight: 600; padding: 2px 8px; border-radius: 4px;
  background: rgba(0,0,0,0.06); color: var(--text-2);
}

.lesson-card-body { padding: 18px 20px 20px; flex: 1; display: flex; flex-direction: column; }
.lesson-card-body h3 {
  font-family: var(--font-head); font-size: 1rem; font-weight: 700;
  color: var(--text); line-height: 1.28; margin-bottom: 8px; letter-spacing: -0.01em;
}
.lesson-card-body p { font-size: 0.83rem; color: var(--text-2); line-height: 1.6; margin-bottom: 14px; flex: 1; }
.card-footer {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 0.75rem; color: var(--text-3);
  padding-top: 12px; border-top: 1px solid var(--border);
}
.card-read-link {
  font-size: 0.82rem; font-weight: 600; color: var(--accent); text-decoration: none;
  display: flex; align-items: center; gap: 4px;
}
.lesson-card:hover .card-read-link { text-decoration: underline; }

/* ── RESPONSIVE ── */
@media (max-width: 900px) {
  .lesson-cards { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .nav-links { display: none; }
  .container { padding: 0 20px; }
  .lesson-cards { grid-template-columns: 1fr; }
  .lesson-nav-bottom { flex-direction: column; align-items: stretch; }
  .footer-grid { grid-template-columns: 1fr; }
}