/* ========================================================================
   AP Slides System - Shared Stylesheet
   Visual baseline mirrors ap-study.com (forest-green root + cream)
   Subject palettes applied per-unit via :root --primary/--secondary/--accent
   ======================================================================== */

:root{
  --primary:#1A365D;        /* subject accent (overridden per unit) */
  --primary-light:#2C5282;
  --secondary:#D4AF37;       /* gold/math accent */
  --bg:#F8F6F1;              /* cream */
  --bg-soft:#FFFFFF;
  --dark:#15211A;
  --text:#1F2937;
  --gray:#6B7280;
  --gray-light:#9CA3AF;
  --border:#E5E7EB;
  --light:#F4F6F3;
  --radius:18px;
  --radius-sm:12px;
  --transition:.25s cubic-bezier(.4,0,.2,1);
  --shadow:0 4px 18px rgba(0,0,0,.06);
  --shadow-hover:0 14px 38px rgba(0,0,0,.12);
  --shadow-lg:0 24px 56px rgba(0,0,0,.16);
  /* ap-study.com brand */
  --forest:#1B4D3E;
  --coral:#E86A56;
  --lime:#A3D9B1;
}

*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:'Inter',-apple-system,BlinkMacSystemFont,sans-serif;color:var(--text);background:var(--bg);line-height:1.6;-webkit-font-smoothing:antialiased}
a{text-decoration:none;color:inherit}
img{max-width:100%;display:block}

/* ===== Top Nav ===== */
.navbar{position:fixed;top:0;left:0;right:0;z-index:1000;background:rgba(255,255,255,.94);backdrop-filter:blur(16px);-webkit-backdrop-filter:blur(16px);border-bottom:1px solid var(--border);height:60px;display:flex;align-items:center;justify-content:space-between;padding:0 32px}
.navbar .logo{font-weight:900;font-size:1.05rem;display:flex;align-items:center;gap:9px;color:var(--forest)}
.navbar .logo i{color:var(--coral);font-size:1.1rem}
.navbar .crumbs{display:flex;align-items:center;gap:8px;font-size:.78rem;color:var(--gray);font-weight:500}
.navbar .crumbs a{color:var(--gray);transition:color .2s}
.navbar .crumbs a:hover{color:var(--forest)}
.navbar .crumbs .sep{color:var(--gray-light);font-size:.7rem}
.navbar .crumbs .current{color:var(--dark);font-weight:700}
.navbar nav.right{display:flex;align-items:center;gap:18px}
.navbar nav.right a{color:var(--gray);font-size:.78rem;font-weight:500;transition:color .2s}
.navbar nav.right a:hover{color:var(--forest)}
@media(max-width:768px){.navbar{padding:0 16px}.navbar .crumbs{font-size:.7rem;max-width:50%;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}}

/* ===== Hero (subject index) ===== */
.hero{padding:120px 24px 60px;text-align:center;background:linear-gradient(180deg,#FFFFFF 0%,var(--bg) 100%)}
.hero .kicker{display:inline-flex;align-items:center;gap:8px;background:rgba(232,106,86,.1);color:var(--coral);font-size:.75rem;font-weight:800;letter-spacing:1px;padding:7px 16px;border-radius:30px;margin-bottom:18px;text-transform:uppercase}
.hero h1{font-size:clamp(2rem,5vw,3.2rem);font-weight:900;line-height:1.1;letter-spacing:-.02em;margin-bottom:14px;color:var(--forest)}
.hero h1 span{color:#C45642}
.hero p{font-size:1.05rem;color:var(--gray);max-width:680px;margin:0 auto;line-height:1.7}
.hero .stats{margin-top:36px;display:flex;justify-content:center;gap:36px;flex-wrap:wrap}
.hero .stats .stat{text-align:center}
.hero .stats .num{font-size:2rem;font-weight:900;color:var(--forest);line-height:1}
.hero .stats .lbl{font-size:.72rem;color:var(--gray);letter-spacing:1px;text-transform:uppercase;margin-top:6px}

/* ===== Subject Index Grid ===== */
.subjects-wrap{max-width:1280px;margin:0 auto;padding:20px 24px 80px}
.subjects-wrap .filter-bar{display:flex;justify-content:center;flex-wrap:wrap;gap:8px;margin-bottom:36px;padding:24px 16px;border-bottom:1px solid var(--border)}
.filter-btn{appearance:none;border:1.5px solid var(--border);background:#fff;color:var(--gray);font-family:inherit;font-size:.78rem;font-weight:700;padding:8px 16px;border-radius:30px;cursor:pointer;transition:all .2s;letter-spacing:.3px}
.filter-btn:hover{border-color:var(--forest);color:var(--forest)}
.filter-btn.active{background:var(--forest);color:#fff;border-color:var(--forest)}

.cat-section{margin-bottom:42px}
.cat-title{font-size:1.05rem;font-weight:800;color:var(--dark);margin-bottom:18px;padding-left:6px;display:flex;align-items:center;gap:10px}
.cat-title .badge{margin-left:auto;font-size:.7rem;font-weight:700;background:var(--light);color:var(--gray);padding:4px 12px;border-radius:20px}
.cat-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:14px}

.subject-card{background:var(--bg-soft);border:1.5px solid var(--border);border-radius:var(--radius);padding:22px 20px 20px;display:flex;flex-direction:column;gap:10px;cursor:pointer;transition:all var(--transition);position:relative;overflow:hidden}
.subject-card::before{content:'';position:absolute;top:0;left:0;right:0;height:4px;background:var(--c);opacity:.85}
.subject-card .icon{font-size:1.75rem;line-height:1}
.subject-card .name{font-size:.98rem;font-weight:800;color:var(--dark);line-height:1.3}
.subject-card .meta{font-size:.72rem;color:var(--gray);margin-top:auto}
.subject-card:hover{transform:translateY(-5px);box-shadow:var(--shadow-hover);border-color:transparent}

/* subject palette */
.c-math{--c:#1A365D}.c-phys{--c:#4C51BF}.c-chem{--c:#276749}.c-bio{--c:#9B2C2C}
.c-hist{--c:#744210}.c-econ{--c:#C05621}.c-eng{--c:#2D3748}.c-cs{--c:#285E61}
.c-psych{--c:#553C9A}.c-art{--c:#822727}.c-lang{--c:#1A4D78}

/* ===== Unit Index (inside one subject) ===== */
.unit-wrap{max-width:1100px;margin:0 auto;padding:100px 24px 60px}
.unit-hero{text-align:left;margin-bottom:32px;padding-bottom:28px;border-bottom:1px solid var(--border)}
.unit-hero .badge-row{display:flex;align-items:center;gap:10px;margin-bottom:12px}
.unit-hero .badge{font-size:.7rem;font-weight:800;letter-spacing:1px;padding:5px 12px;border-radius:20px;background:rgba(26,54,93,.1);color:var(--primary);text-transform:uppercase}
.unit-hero h1{font-size:clamp(1.8rem,4vw,2.6rem);font-weight:900;color:var(--dark);margin-bottom:10px;line-height:1.15}
.unit-hero p{font-size:1rem;color:var(--gray);max-width:680px;line-height:1.7}
.unit-hero .pills{margin-top:14px;display:flex;flex-wrap:wrap;gap:8px}
.unit-hero .pill{font-size:.7rem;font-weight:700;color:var(--gray);background:var(--light);padding:4px 10px;border-radius:20px}

.unit-grid{display:flex;flex-direction:column;gap:14px}
.unit-card{background:var(--bg-soft);border:1.5px solid var(--border);border-radius:var(--radius);padding:24px 26px;display:flex;align-items:center;gap:22px;cursor:pointer;transition:all var(--transition);position:relative;overflow:hidden}
.unit-card::before{content:'';position:absolute;left:0;top:0;bottom:0;width:5px;background:var(--primary)}
.unit-card .unum{font-size:2.4rem;font-weight:900;color:var(--primary);line-height:1;flex-shrink:0;width:54px;text-align:center}
.unit-card .uinfo{flex:1;min-width:0}
.unit-card .uinfo .uname{font-size:1.1rem;font-weight:800;color:var(--dark);margin-bottom:5px;line-height:1.3}
.unit-card .uinfo .udesc{font-size:.82rem;color:var(--gray);line-height:1.55;margin-bottom:8px}
.unit-card .uinfo .ulessons{display:flex;flex-wrap:wrap;gap:5px}
.unit-card .uinfo .ulessons .lpill{font-size:.66rem;font-weight:600;color:var(--primary);background:rgba(26,54,93,.08);padding:3px 9px;border-radius:12px}
.unit-card .ustats{display:flex;flex-direction:column;align-items:flex-end;gap:4px;flex-shrink:0}
.unit-card .ustats .pn{font-size:.7rem;color:var(--gray);font-weight:700}
.unit-card .ustats .pn strong{font-size:1.15rem;color:var(--dark)}
.unit-card .ugo{width:38px;height:38px;border-radius:50%;background:var(--primary);color:#fff;display:flex;align-items:center;justify-content:center;font-size:.9rem;transition:transform .2s}
.unit-card:hover{transform:translateX(6px);box-shadow:var(--shadow-hover);border-color:transparent}
.unit-card:hover .ugo{transform:translateX(4px)}

/* ===== Slide Deck Layout ===== */
.deck{position:fixed;inset:0;top:60px;background:linear-gradient(160deg,#FAF7F2 0%,var(--bg) 100%);display:flex;overflow:hidden}
.deck-cols{display:flex;width:100%;height:100%}

/* Page list (left) */
.page-rail{width:230px;flex-shrink:0;background:rgba(255,255,255,.7);border-right:1px solid var(--border);overflow-y:auto;padding:14px 12px 14px 14px;display:flex;flex-direction:column;gap:4px}
.page-rail .rail-title{font-size:.68rem;font-weight:800;letter-spacing:1px;color:var(--gray);text-transform:uppercase;padding:6px 10px 12px;display:flex;justify-content:space-between;align-items:center}
.page-rail .rail-title .count{background:var(--primary);color:#fff;font-size:.65rem;padding:2px 8px;border-radius:10px}
.page-item{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:10px;cursor:pointer;transition:all .15s;font-size:.78rem;color:var(--gray);border:1px solid transparent}
.page-item .pidx{width:24px;height:24px;border-radius:6px;background:var(--light);color:var(--gray);font-size:.7rem;font-weight:800;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:all .15s}
.page-item .ptxt{font-size:.74rem;font-weight:500;line-height:1.3;flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.page-item:hover{background:var(--light);color:var(--dark)}
.page-item.active{background:rgba(26,54,93,.1);color:var(--primary);font-weight:700}
.page-item.active .pidx{background:var(--primary);color:#fff}
.page-item.visited .pidx::after{content:'';width:5px;height:5px;border-radius:50%;background:var(--gray-light)}
@media(max-width:900px){.page-rail{display:none}}

/* Stage */
.stage{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:24px 36px 90px;position:relative;overflow:hidden;min-width:0}
.slide-card{width:100%;max-width:920px;aspect-ratio:16/9;max-height:100%;background:#fff;border-radius:18px;box-shadow:0 18px 44px rgba(0,0,0,.10),0 4px 12px rgba(0,0,0,.05);overflow:hidden;display:flex;flex-direction:column;position:relative;border-top:5px solid var(--primary)}
.slide-inner{flex:1;min-height:0;display:flex;flex-direction:column;padding:36px 46px 40px;overflow-y:auto;overscroll-behavior:contain;scrollbar-width:thin;scrollbar-color:rgba(0,0,0,.18) transparent}
.slide-inner::-webkit-scrollbar{width:9px}
.slide-inner::-webkit-scrollbar-thumb{background:rgba(0,0,0,.16);border-radius:5px}
.slide-inner::-webkit-scrollbar-thumb:hover{background:rgba(0,0,0,.28)}
.slide-tag{font-size:.7rem;font-weight:800;letter-spacing:1.5px;color:var(--primary);text-transform:uppercase;margin-bottom:14px;display:flex;align-items:center;gap:10px}
.slide-tag .divider{width:24px;height:2px;background:var(--secondary)}
.slide-title{font-size:1.95rem;font-weight:900;color:var(--dark);line-height:1.15;margin-bottom:6px;letter-spacing:-.01em}
.slide-subtitle{font-size:.95rem;color:var(--gray);font-weight:500;margin-bottom:22px}
.slide-body{flex:1;overflow:visible}
.slide-page-num{position:absolute;bottom:14px;right:22px;font-size:.7rem;font-weight:700;color:var(--gray-light);letter-spacing:1px;background:rgba(255,255,255,.85);padding:2px 6px;border-radius:6px}
.slide-page-num .unit{color:var(--primary)}

/* 梗图 / 笑话组件 — 每个课件穿插用 */
.joke-box{display:flex;gap:14px;align-items:flex-start;background:linear-gradient(135deg,var(--light),#fff);border:1.5px dashed var(--secondary);border-radius:14px;padding:14px 18px;margin-top:auto;margin-bottom:6px;position:relative}
.joke-box .jemoji{font-size:1.7rem;line-height:1.2;flex-shrink:0}
.joke-box .jtag{font-size:.6rem;font-weight:800;letter-spacing:1.4px;color:var(--secondary);text-transform:uppercase;margin-bottom:4px}
.joke-box .jtxt{font-size:.86rem;color:var(--dark);line-height:1.55}
.joke-box .jtxt em{color:var(--gray);font-size:.8rem}
.meme-strip{margin:14px 0 4px;text-align:center}
.meme-strip svg{max-width:100%;height:auto;border:1px solid var(--border);border-radius:14px;background:#fff}
.meme-strip .msrc{font-size:.66rem;color:var(--gray-light);margin-top:5px;letter-spacing:.5px}

/* slide content types */
.def-box{background:linear-gradient(135deg,rgba(26,54,93,.04),rgba(26,54,93,.02));border-left:4px solid var(--primary);padding:18px 22px;border-radius:10px;margin:12px 0}
.def-box .label{font-size:.7rem;font-weight:800;color:var(--primary);text-transform:uppercase;letter-spacing:1.2px;margin-bottom:6px}
.def-box .content{font-size:1.05rem;color:var(--dark);line-height:1.55}

.formula-box{background:linear-gradient(135deg,#1A365D,#2C5282);color:#fff;padding:22px 26px;border-radius:12px;margin:14px 0;text-align:center;position:relative;overflow:hidden}
.formula-box::before{content:'';position:absolute;top:-30px;right:-30px;width:120px;height:120px;background:rgba(212,175,55,.15);border-radius:50%}
.formula-box .ftitle{font-size:.7rem;font-weight:800;letter-spacing:1.5px;color:var(--secondary);text-transform:uppercase;margin-bottom:10px}
.formula-box .fmath{font-family:'Georgia',serif;font-size:1.55rem;font-weight:600;letter-spacing:.5px;color:#fff;margin:8px 0;position:relative}
.formula-box .fdesc{font-size:.85rem;color:rgba(255,255,255,.85);line-height:1.5;position:relative}

.bullets{padding-left:0;list-style:none}
.bullets li{padding:9px 0 9px 24px;position:relative;font-size:.95rem;color:var(--dark);line-height:1.55;border-bottom:1px dashed var(--border)}
.bullets li:last-child{border-bottom:none}
.bullets li::before{content:'';position:absolute;left:4px;top:18px;width:8px;height:8px;background:var(--secondary);border-radius:50%}
.bullets li strong{color:var(--primary)}

.two-col{display:grid;grid-template-columns:1.1fr 1fr;gap:24px;align-items:flex-start}
.two-col img{max-width:100%;border-radius:10px;border:1px solid var(--border)}

.kw-row{display:flex;flex-wrap:wrap;gap:8px;margin:14px 0}
.kw{font-size:.78rem;font-weight:600;color:var(--primary);background:rgba(26,54,93,.08);padding:6px 12px;border-radius:18px;border:1px solid rgba(26,54,93,.15)}

.example-box{background:#FFF;border:1.5px solid var(--border);border-radius:14px;padding:18px 22px;margin:10px 0}
.example-box .ex-tag{font-size:.68rem;font-weight:800;letter-spacing:1.2px;color:var(--coral);text-transform:uppercase;margin-bottom:6px}
.example-box .ex-q{font-size:.95rem;color:var(--dark);line-height:1.55;margin-bottom:10px}
.example-box .ex-q .num{font-weight:800;color:var(--primary);margin-right:6px}
.example-box .ex-step{padding:8px 12px;background:var(--light);border-radius:8px;font-size:.85rem;color:var(--dark);margin-top:6px;font-family:'Georgia',serif}
.example-box .ex-step .stepno{font-size:.7rem;font-weight:800;color:var(--primary);margin-right:8px}

.video-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px;margin-top:14px}
.video-card{background:#fff;border:1px solid var(--border);border-radius:12px;padding:14px 16px;display:flex;flex-direction:column;gap:8px;transition:all .2s;cursor:pointer}
.video-card:hover{border-color:var(--coral);transform:translateY(-3px);box-shadow:var(--shadow)}
.video-card .vtag{font-size:.65rem;font-weight:800;letter-spacing:1px;color:var(--coral);text-transform:uppercase}
.video-card .vtitle{font-size:.88rem;font-weight:700;color:var(--dark);line-height:1.35}
.video-card .vmeta{display:flex;justify-content:space-between;font-size:.7rem;color:var(--gray)}
.video-card .vplay{align-self:flex-end;width:32px;height:32px;border-radius:50%;background:var(--coral);color:#fff;display:flex;align-items:center;justify-content:center}

.cover{display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:60px 40px;height:100%;background:linear-gradient(135deg,#1A365D 0%,#0F2444 100%);color:#fff;position:relative;overflow:hidden}
.cover::before{content:'∫';position:absolute;top:-30px;right:-30px;font-size:320px;color:rgba(212,175,55,.18);font-family:Georgia,serif;line-height:1}
.cover .cov-sub{font-size:.85rem;letter-spacing:3px;color:var(--secondary);text-transform:uppercase;margin-bottom:14px;font-weight:600}
.cover .cov-title{font-size:3.6rem;font-weight:900;line-height:1.05;margin-bottom:18px;letter-spacing:-.02em}
.cover .cov-meta{font-size:1.05rem;color:rgba(255,255,255,.85);margin-bottom:30px;max-width:560px;line-height:1.6}
.cover .cov-chip{display:inline-flex;align-items:center;gap:8px;border:1.5px solid rgba(212,175,55,.5);padding:8px 18px;border-radius:30px;font-size:.8rem;color:var(--secondary);font-weight:600}

/* hero simple */
.welcome{display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;height:100%;padding:40px;background:linear-gradient(135deg,#FAF7F2,#F0E8D8);position:relative;overflow:hidden}
.welcome .wemoji{font-size:5rem;margin-bottom:18px}
.welcome h2{font-size:2.8rem;font-weight:900;color:var(--dark);margin-bottom:14px;letter-spacing:-.02em}
.welcome p{font-size:1.1rem;color:var(--gray);max-width:560px;line-height:1.6}

/* quiz MCQ */
.quiz-q{font-size:1.15rem;font-weight:700;color:var(--dark);margin-bottom:16px;line-height:1.4}
.quiz-opts{display:flex;flex-direction:column;gap:10px;margin-bottom:14px}
.quiz-opt{display:flex;align-items:center;gap:14px;padding:14px 18px;background:#fff;border:1.5px solid var(--border);border-radius:12px;cursor:pointer;transition:all .15s;font-size:.92rem;color:var(--dark)}
.quiz-opt:hover{border-color:var(--primary);background:var(--light)}
.quiz-opt .letter{width:30px;height:30px;border-radius:8px;background:var(--light);color:var(--primary);font-weight:800;display:flex;align-items:center;justify-content:center;font-size:.85rem;flex-shrink:0}
.quiz-opt.correct{background:rgba(61,139,110,.12);border-color:#3D8B6E;color:#1B4D3E}
.quiz-opt.correct .letter{background:#3D8B6E;color:#fff}
.quiz-opt.wrong{background:rgba(232,106,86,.12);border-color:var(--coral);color:#7F1D1D}
.quiz-opt.wrong .letter{background:var(--coral);color:#fff}
.quiz-key{margin-top:10px;padding:14px 18px;background:rgba(61,139,110,.1);border-left:4px solid #3D8B6E;border-radius:8px;font-size:.88rem;color:#1B4D3E;display:none}
.quiz-key.show{display:block}

/* nav controls (bottom) */
.nav-controls{position:absolute;bottom:0;left:0;right:0;height:74px;display:flex;align-items:center;justify-content:space-between;padding:0 36px;background:rgba(255,255,255,.85);backdrop-filter:blur(10px);border-top:1px solid var(--border)}
.nav-info{font-size:.72rem;color:var(--gray);font-weight:600;display:flex;align-items:center;gap:12px;letter-spacing:.5px;text-transform:uppercase}
.nav-info .label{background:var(--primary);color:#fff;padding:4px 10px;border-radius:8px;font-size:.7rem}
.nav-info .pgs{color:var(--dark);font-weight:800;font-size:.85rem}
.nav-info .pgs .cur{color:var(--primary);font-size:.95rem}

.progress-bar{position:absolute;bottom:74px;left:0;right:0;height:3px;background:rgba(0,0,0,.04);overflow:hidden}
.progress-bar .fill{height:100%;background:linear-gradient(90deg,var(--primary),var(--secondary));transition:width .25s ease}

.nav-buttons{display:flex;gap:10px}
.nav-btn{appearance:none;border:1.5px solid var(--border);background:#fff;color:var(--dark);font-family:inherit;font-size:.82rem;font-weight:700;padding:9px 18px;border-radius:30px;cursor:pointer;display:inline-flex;align-items:center;gap:8px;transition:all .15s}
.nav-btn:hover:not(:disabled){border-color:var(--primary);color:var(--primary);transform:translateY(-1px)}
.nav-btn:disabled{opacity:.4;cursor:not-allowed}
.nav-btn.primary{background:var(--primary);color:#fff;border-color:var(--primary)}
.nav-btn.primary:hover:not(:disabled){background:var(--primary-light);border-color:var(--primary-light);color:#fff}

/* fade slide */
.fade-enter{animation:fadeIn .35s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:translateY(0)}}

/* scrollbar */
.page-rail::-webkit-scrollbar{width:6px}
.page-rail::-webkit-scrollbar-thumb{background:rgba(0,0,0,.12);border-radius:3px}
.page-rail::-webkit-scrollbar-thumb:hover{background:rgba(0,0,0,.22)}

/* misc */
.note{background:rgba(212,175,55,.1);border:1px dashed var(--secondary);padding:14px 18px;border-radius:10px;font-size:.88rem;color:#7C5E0D;line-height:1.55}
.note strong{color:#5C4308}

.pill-row{display:flex;flex-wrap:wrap;gap:8px;margin-bottom:18px}
.tag-pill{font-size:.7rem;font-weight:800;letter-spacing:.5px;color:#fff;background:var(--primary);padding:5px 12px;border-radius:18px;text-transform:uppercase}

table.bordered{width:100%;border-collapse:collapse;margin:14px 0;font-size:.85rem}
table.bordered th{background:var(--primary);color:#fff;padding:10px 12px;text-align:left;font-size:.78rem;font-weight:700;text-transform:uppercase;letter-spacing:.5px}
table.bordered td{padding:10px 12px;border-bottom:1px solid var(--border);color:var(--dark)}
table.bordered tr:nth-child(even) td{background:var(--light)}

.callout{display:flex;align-items:flex-start;gap:14px;padding:14px 18px;background:#FEF7E6;border-left:4px solid #F2C94C;border-radius:8px;margin:12px 0}
.callout .ci{font-size:1.4rem;flex-shrink:0}
.callout .ct{font-size:.88rem;color:#5C4308;line-height:1.55}
.callout .ct strong{color:#3A2D08}

.error-box{background:#FEF2F2;border-left:4px solid #DC2626;padding:14px 18px;border-radius:8px;margin:10px 0}
.error-box h4{color:#991B1B;font-size:.9rem;font-weight:800;margin-bottom:6px}
.error-box p{color:#7F1D1D;font-size:.85rem;line-height:1.55}

/* footer */
.foot{padding:60px 24px 80px;background:var(--bg-soft);border-top:1px solid var(--border);text-align:center}
.foot p{font-size:.85rem;color:var(--gray)}
.foot a{color:var(--coral);font-weight:700}

@media(max-width:768px){
  .two-col{grid-template-columns:1fr}
  .video-grid{grid-template-columns:1fr}
  .slide-inner{padding:22px 24px 22px}
  .slide-title{font-size:1.4rem}
  .stage{padding:14px 12px 88px}
  .nav-controls{padding:0 16px}
}