/* ============================================
   BRAHMAPUTRA GYMNASIUM — EXERCISE GUIDE
   Token system:
   Color:  --bg #0a0c11 · --bg-card #12151d · --fire #ff4b2b
           (energy/intensity) · --river #2ea8ff (Brahmaputra
           river — the site's namesake) · --gold #ffb347
           (highlight) · --text #f2f4f8 · --muted #93a0b3
   Type:   Poppins (display / headings) + Inter (body)
   Signature: an animated "river flow" current running
   beneath the hero, and a per-card "rep pulse" dot that
   beats like a heartbeat — tying the river name to the
   rhythm of training.
   ============================================ */

:root {
    --bg: #0a0c11;
    --bg-alt: #0d1016;
    --bg-card: #12151d;
    --bg-card-hover: #171b25;
    --border: #232836;
    --fire: #ff4b2b;
    --fire-light: #ff7a52;
    --river: #2ea8ff;
    --river-light: #6fc4ff;
    --gold: #ffb347;
    --text: #f2f4f8;
    --muted: #93a0b3;
    --green: #38d996;
    --amber: #ffcc4d;
    --red: #ff5c66;
}

* { 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; }
}

body {
    margin: 0;
    background: var(--bg);
    color: var(--text);
    font-family: 'Inter', sans-serif;
    line-height: 1.6;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5 {
    font-family: 'Poppins', sans-serif;
    margin: 0;
    color: var(--text);
}

p { margin: 0; }

a { text-decoration: none; color: inherit; }

.container {
    max-width: 1180px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Scroll progress + back to top ===== */
#progress-bar {
    position: fixed;
    top: 0; left: 0;
    height: 3px;
    width: 0%;
    background: linear-gradient(90deg, var(--river), var(--fire));
    z-index: 1000;
    transition: width 0.1s ease-out;
}

#backToTop {
    position: fixed;
    bottom: 26px;
    right: 26px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--fire), var(--gold));
    color: #fff;
    border: none;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(255, 75, 43, 0.35);
    z-index: 999;
    transition: transform 0.2s ease;
}
#backToTop.show { display: flex; }
#backToTop:hover { transform: translateY(-3px); }

/* ===== Top bar ===== */
.eg-topbar {
    background: var(--bg-alt);
    border-bottom: 1px solid var(--border);
}
.eg-topbar-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 24px;
    flex-wrap: wrap;
    gap: 8px;
}
.eg-back {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 600;
    font-size: 14px;
    color: var(--text);
    transition: color 0.2s ease;
}
.eg-back:hover { color: var(--river-light); }
.eg-crumb {
    font-size: 13px;
    color: var(--muted);
    display: flex;
    align-items: center;
    gap: 6px;
}
.eg-crumb i { font-size: 10px; }

/* ===== Hero ===== */
.eg-hero {
    position: relative;
    padding: 70px 0 60px;
    background: radial-gradient(ellipse at top, #131826 0%, var(--bg) 65%);
    overflow: hidden;
    border-bottom: 1px solid var(--border);
}

/* Signature: animated river-flow current, referencing the
   Brahmaputra river the gym is named after */
.eg-river {
    position: absolute;
    left: -10%;
    right: -10%;
    bottom: -40px;
    height: 140px;
    background: linear-gradient(90deg,
        transparent 0%,
        rgba(46, 168, 255, 0.14) 20%,
        rgba(255, 75, 43, 0.10) 50%,
        rgba(46, 168, 255, 0.14) 80%,
        transparent 100%);
    filter: blur(30px);
    transform: skewY(-3deg);
    animation: riverFlow 12s ease-in-out infinite;
}
@keyframes riverFlow {
    0%   { transform: skewY(-3deg) translateX(-4%); }
    50%  { transform: skewY(-3deg) translateX(4%); }
    100% { transform: skewY(-3deg) translateX(-4%); }
}

.eg-hero-inner { position: relative; text-align: center; z-index: 1; }
.eg-eyebrow {
    display: inline-block;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 2px;
    color: var(--river-light);
    background: rgba(46, 168, 255, 0.1);
    border: 1px solid rgba(46, 168, 255, 0.3);
    padding: 6px 16px;
    border-radius: 999px;
    margin-bottom: 18px;
}
.eg-hero h1 {
    font-size: clamp(28px, 5vw, 46px);
    font-weight: 800;
    letter-spacing: -0.5px;
}
.eg-sub {
    max-width: 640px;
    margin: 16px auto 0;
    color: var(--muted);
    font-size: 16px;
}

.eg-search {
    max-width: 460px;
    margin: 32px auto 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    display: flex;
    align-items: center;
    padding: 4px 18px;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.eg-search:focus-within {
    border-color: var(--river);
    box-shadow: 0 0 0 3px rgba(46, 168, 255, 0.15);
}
.eg-search i { color: var(--muted); margin-right: 10px; }
.eg-search input {
    background: none;
    border: none;
    outline: none;
    color: var(--text);
    font-family: 'Inter', sans-serif;
    font-size: 15px;
    padding: 12px 0;
    width: 100%;
}
.eg-search input::placeholder { color: var(--muted); }

/* ===== Quick nav ===== */
.eg-quicknav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10, 12, 17, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}
.eg-quicknav-inner {
    display: flex;
    gap: 6px;
    overflow-x: auto;
    padding: 12px 24px;
    scrollbar-width: thin;
}
.eg-quicknav-inner::-webkit-scrollbar { height: 4px; }
.eg-quicknav-inner::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
.eg-quicknav a {
    flex: none;
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    font-weight: 600;
    color: var(--muted);
    padding: 8px 14px;
    border-radius: 999px;
    border: 1px solid transparent;
    transition: all 0.2s ease;
    white-space: nowrap;
}
.eg-quicknav a:hover { color: var(--text); border-color: var(--border); }
.eg-quicknav a.active {
    color: #fff;
    background: linear-gradient(135deg, var(--fire), var(--gold));
    border-color: transparent;
}

.eg-count {
    text-align: center;
    color: var(--muted);
    font-size: 13px;
    padding: 18px 24px 0;
}

/* ===== Group sections ===== */
.eg-group { padding: 56px 0; border-bottom: 1px solid var(--border); }
.eg-group:nth-child(even) { background: var(--bg-alt); }

.eg-group-head {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    margin-bottom: 32px;
}
.eg-group-icon {
    flex: none;
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    color: #fff;
    background: linear-gradient(135deg, var(--river), var(--fire));
}
.eg-group-tag {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1.5px;
    color: var(--gold);
}
.eg-group-head h2 {
    font-size: 26px;
    margin: 4px 0 8px;
}
.eg-group-head p {
    color: var(--muted);
    font-size: 14.5px;
    max-width: 620px;
}

.eg-cards {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

/* ===== Exercise card ===== */
.ex-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    overflow: hidden;
    transition: border-color 0.2s ease, transform 0.2s ease;
}
.ex-card:hover { border-color: rgba(46, 168, 255, 0.35); }
.ex-card.hidden { display: none; }

.ex-head {
    width: 100%;
    background: none;
    border: none;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 18px 20px;
    cursor: pointer;
    text-align: left;
    font-family: inherit;
}
.ex-emoji { font-size: 26px; flex: none; }
.ex-title { flex: 1; min-width: 0; }
.ex-title h3 { font-size: 17px; font-weight: 700; margin-bottom: 8px; }
.ex-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tag {
    font-size: 11.5px;
    font-weight: 600;
    color: var(--muted);
    background: var(--bg-alt);
    border: 1px solid var(--border);
    padding: 4px 10px;
    border-radius: 999px;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}
.tag i { font-size: 10px; }
.diff-beginner { color: var(--green); border-color: rgba(56, 217, 150, 0.35); }
.diff-intermediate { color: var(--amber); border-color: rgba(255, 204, 77, 0.35); }
.diff-advanced { color: var(--red); border-color: rgba(255, 92, 102, 0.35); }

/* Signature micro-detail: a "rep pulse" heartbeat dot,
   echoing the rhythm of a training set */
.ex-pulse {
    flex: none;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--fire);
    box-shadow: 0 0 0 0 rgba(255, 75, 43, 0.5);
    animation: repPulse 2.2s ease-out infinite;
}
@keyframes repPulse {
    0%   { box-shadow: 0 0 0 0 rgba(255, 75, 43, 0.5); }
    70%  { box-shadow: 0 0 0 9px rgba(255, 75, 43, 0); }
    100% { box-shadow: 0 0 0 0 rgba(255, 75, 43, 0); }
}

.ex-chevron {
    flex: none;
    color: var(--muted);
    transition: transform 0.3s ease;
}
.ex-card.open .ex-chevron { transform: rotate(180deg); color: var(--river-light); }

.ex-body {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.35s ease;
}
.ex-card.open .ex-body { grid-template-rows: 1fr; }
.ex-body-inner {
    overflow: hidden;
    padding: 0 20px;
}
.ex-card.open .ex-body-inner {
    padding: 4px 20px 22px;
}

.ex-body-inner h4 {
    font-size: 13px;
    letter-spacing: 0.5px;
    color: var(--river-light);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.ex-body-inner ol {
    margin: 0 0 18px;
    padding-left: 20px;
    color: #d7dce5;
    font-size: 14.5px;
}
.ex-body-inner ol li { margin-bottom: 8px; }
.ex-body-inner ol li:last-child { margin-bottom: 0; }

.ex-grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    margin-bottom: 18px;
}
.ex-box {
    background: var(--bg-alt);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 14px 16px;
}
.ex-box h5 {
    font-size: 12.5px;
    display: flex;
    align-items: center;
    gap: 7px;
    margin-bottom: 8px;
}
.ex-box.tip h5 { color: var(--gold); }
.ex-box.mistake h5 { color: var(--red); }
.ex-box p, .ex-box ul { font-size: 13.5px; color: var(--muted); margin: 0; padding-left: 18px; }
.ex-box ul li { margin-bottom: 4px; }

.ex-meta {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}
.ex-meta span {
    font-size: 12.5px;
    font-weight: 600;
    color: var(--text);
    background: linear-gradient(135deg, rgba(46,168,255,0.12), rgba(255,75,43,0.12));
    border: 1px solid var(--border);
    padding: 6px 12px;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.ex-meta i { color: var(--river-light); font-size: 11px; }

/* ===== Safety note ===== */
.eg-note { padding: 40px 0 70px; }
.eg-note-inner {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-left: 3px solid var(--gold);
    border-radius: 14px;
    padding: 20px 24px;
}
.eg-note-inner i { color: var(--gold); font-size: 20px; margin-top: 2px; }
.eg-note-inner p { color: var(--muted); font-size: 13.5px; }

/* ===== Footer ===== */
.eg-footer { padding: 30px 0; border-top: 1px solid var(--border); }
.eg-footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
}
.eg-footer-inner p { color: var(--muted); font-size: 13.5px; }
.eg-footer-inner a {
    color: var(--river-light);
    font-weight: 600;
    font-size: 13.5px;
    display: flex;
    align-items: center;
    gap: 6px;
}

/* ===== Reveal on scroll ===== */
.reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ===== Responsive ===== */
@media (max-width: 720px) {
    .eg-group-head { flex-direction: column; }
    .ex-grid-2 { grid-template-columns: 1fr; }
    .eg-hero { padding: 50px 0 40px; }
    .ex-head { align-items: flex-start; }
    .ex-pulse { margin-top: 8px; }
}

/* ===== Premium visual refinement ===== */
:root {
    --bg: #080b12;
    --bg-alt: #0d1220;
    --bg-card: #111827;
    --bg-card-hover: #162033;
    --border: rgba(148, 163, 184, 0.16);
    --text: #f8fafc;
    --muted: #94a3b8;
    --river: #38bdf8;
    --river-light: #7dd3fc;
    --fire: #f97316;
    --fire-light: #fb923c;
    --gold: #fbbf24;
}

body {
    background: radial-gradient(circle at 80% -10%, rgba(14, 165, 233, 0.13), transparent 26rem), radial-gradient(circle at 0% 36%, rgba(249, 115, 22, 0.07), transparent 24rem), var(--bg);
    letter-spacing: 0.005em;
}
.container { max-width: 1200px; }
.eg-topbar { background: rgba(8, 11, 18, 0.82); backdrop-filter: blur(16px); }
.eg-topbar-inner { min-height: 62px; padding-top: 12px; padding-bottom: 12px; }
.eg-back { color: #e2e8f0; }
.eg-back i { color: var(--river); }

.eg-hero { padding: 94px 0 82px; background: linear-gradient(180deg, rgba(15, 23, 42, 0.5), rgba(8, 11, 18, 0.08)), radial-gradient(ellipse at 50% -20%, #1d3555 0%, var(--bg) 66%); }
.eg-hero::before { content: ""; position: absolute; inset: 0; pointer-events: none; opacity: 0.32; background-image: linear-gradient(rgba(125,211,252,.045) 1px, transparent 1px), linear-gradient(90deg, rgba(125,211,252,.045) 1px, transparent 1px); background-size: 42px 42px; mask-image: linear-gradient(to bottom, #000, transparent 85%); }
.eg-eyebrow { color: #bae6fd; background: rgba(14, 165, 233, 0.12); border-color: rgba(56, 189, 248, 0.32); box-shadow: inset 0 1px rgba(255,255,255,.08); }
.eg-hero h1 { font-size: clamp(32px, 5vw, 54px); letter-spacing: -1.5px; line-height: 1.12; }
.eg-sub { max-width: 700px; }
.eg-search { max-width: 560px; padding: 5px 18px; border-radius: 14px; background: rgba(15, 23, 42, 0.82); box-shadow: 0 18px 45px rgba(0, 0, 0, .22), inset 0 1px rgba(255,255,255,.04); }
.eg-search input { padding: 14px 0; }

.eg-quicknav { background: rgba(8, 11, 18, 0.78); }
.eg-quicknav-inner { gap: 8px; padding-top: 13px; padding-bottom: 13px; }
.eg-quicknav a { background: rgba(148, 163, 184, 0.04); }
.eg-quicknav a:hover { background: rgba(56, 189, 248, 0.1); border-color: rgba(56, 189, 248, 0.25); }
.eg-quicknav a.active { box-shadow: 0 8px 18px rgba(249, 115, 22, .22); }
.eg-count { padding-top: 26px; color: #64748b; }

.eg-group { padding: 76px 0; border-bottom-color: rgba(148, 163, 184, 0.1); }
.eg-group:nth-child(even) { background: rgba(15, 23, 42, 0.32); }
.eg-group-head { gap: 18px; margin-bottom: 30px; }
.eg-group-icon { width: 58px; height: 58px; border: 1px solid rgba(255,255,255,.18); box-shadow: 0 12px 25px rgba(0,0,0,.25), inset 0 1px rgba(255,255,255,.2); }
.chest-icon { background: linear-gradient(135deg, #fb7185, #f97316); }.back-icon { background: linear-gradient(135deg, #0ea5e9, #6366f1); }.shoulders-icon { background: linear-gradient(135deg, #8b5cf6, #ec4899); }.biceps-icon { background: linear-gradient(135deg, #f59e0b, #ef4444); }.triceps-icon { background: linear-gradient(135deg, #14b8a6, #0ea5e9); }.legs-icon { background: linear-gradient(135deg, #84cc16, #14b8a6); }.abs-icon { background: linear-gradient(135deg, #f97316, #ef4444); }.cardio-icon { background: linear-gradient(135deg, #f43f5e, #ec4899); }
.eg-group-head h2 { font-size: clamp(24px, 3vw, 30px); letter-spacing: -.6px; }

.eg-cards { gap: 12px; }
.ex-card { border-radius: 14px; background: linear-gradient(135deg, rgba(30,41,59,.86), rgba(15,23,42,.96)); box-shadow: 0 6px 18px rgba(0,0,0,.12); }
.ex-card:hover, .ex-card.open { border-color: rgba(56, 189, 248, .38); box-shadow: 0 16px 35px rgba(0,0,0,.18); }
.ex-head { padding: 19px 22px; }.ex-head:focus-visible { outline: 3px solid rgba(56, 189, 248, .55); outline-offset: -3px; }
.ex-emoji { width: 42px; height: 42px; display: grid; place-items: center; font-size: 23px; background: rgba(148, 163, 184, .08); border: 1px solid rgba(148, 163, 184, .12); border-radius: 12px; }
.ex-title h3 { font-size: 16px; margin-bottom: 9px; }.tag { background: rgba(8, 11, 18, .45); border-color: rgba(148,163,184,.15); }
.ex-card.open .ex-head { border-bottom: 1px solid rgba(148,163,184,.12); }.ex-card.open .ex-body-inner { padding: 21px 22px 24px; }
.ex-body-inner ol { color: #cbd5e1; line-height: 1.7; }.ex-box { background: rgba(8, 11, 18, .35); border-color: rgba(148, 163, 184, .12); }.ex-meta span { background: rgba(56, 189, 248, .08); border-color: rgba(56, 189, 248, .16); }
.eg-note-inner { background: linear-gradient(110deg, rgba(251,191,36,.1), rgba(15,23,42,.9) 34%); border-left-width: 4px; box-shadow: 0 14px 30px rgba(0,0,0,.14); }.eg-footer { background: rgba(4, 6, 10, .42); }

@media (max-width: 720px) {
    .container { padding: 0 18px; }.eg-topbar-inner { padding-left: 18px; padding-right: 18px; }.eg-hero { padding: 66px 0 54px; }.eg-hero h1 { font-size: 34px; }.eg-group { padding: 54px 0; }.eg-quicknav-inner { padding-left: 18px; padding-right: 18px; }.ex-head { gap: 12px; padding: 16px; }.ex-emoji { width: 38px; height: 38px; font-size: 20px; }.ex-card.open .ex-body-inner { padding: 18px 16px 20px; }.ex-tags { gap: 5px; }.tag { font-size: 10.5px; padding: 3px 8px; }
}