/* auth.css — student Login / Register. Same look as admin/login.php
   (dark brand panel on the left, form card on the right, light/dark toggle). */
:root, :root[data-theme="dark"] {
    --bg: #020617; --panel: #0b1222; --panel-2: #0f1a2e; --line: rgba(255,255,255,.08);
    --text: #f1f5f9; --muted: #94a3b8; --input: #070d1a;
    --red: #ed1c2e; --red-2: #b3121f; --gold: #ffd900;
    --shadow: 0 30px 80px rgba(0,0,0,.55);
}
:root[data-theme="light"] {
    --bg: #f4f6fb; --panel: #ffffff; --panel-2: #f8fafc; --line: rgba(15,23,42,.1);
    --text: #0f172a; --muted: #64748b; --input: #f1f5f9;
    --shadow: 0 24px 60px rgba(15,23,42,.1);
}
* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Poppins', 'Noto Sans Sinhala', sans-serif; }
body { min-height: 100vh; background: var(--bg); color: var(--text); display: flex; overflow-x: hidden; }

.wrap { display: flex; width: 100%; min-height: 100vh; }

/* ---------- left: brand ---------- */
.brand { flex: 1.15; position: sticky; top: 0; height: 100vh; overflow: hidden; isolation: isolate; color: #fff;
    display: flex; flex-direction: column; justify-content: space-between; gap: 32px; padding: 44px 56px;
    background: radial-gradient(circle at 30% 20%, #3b0a12 0, #12040a 45%, #020617 100%); }
.brand::before { content: ''; position: absolute; inset: 0; z-index: -1; opacity: .35;
    background-image: linear-gradient(rgba(255,255,255,.05) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(255,255,255,.05) 1px, transparent 1px);
    background-size: 44px 44px;
    -webkit-mask-image: radial-gradient(circle at 40% 45%, #000 0, transparent 75%);
            mask-image: radial-gradient(circle at 40% 45%, #000 0, transparent 75%); }
.orb { position: absolute; border-radius: 50%; filter: blur(70px); z-index: -1; }
.orb.r { width: 420px; height: 420px; background: rgba(237,28,46,.35); top: -120px; left: -100px; }
.orb.g { width: 320px; height: 320px; background: rgba(255,217,0,.14); bottom: -100px; right: -60px; }

.brand-top { display: flex; align-items: center; gap: 14px; }
.brand-top img { width: 58px; height: 58px; object-fit: contain; border-radius: 16px; background: #fff; padding: 4px; }
.brand-top .nm { font-size: 22px; font-weight: 800; letter-spacing: -.3px; }
.brand-top small { display: block; font-size: 12px; font-weight: 600; color: rgba(255,255,255,.6); letter-spacing: .6px; }

.brand-mid { max-width: 540px; }
.kicker { display: inline-flex; align-items: center; gap: 8px; font-size: 12px; font-weight: 700; letter-spacing: .8px;
    text-transform: uppercase; color: #fca5a5; background: rgba(237,28,46,.14); border: 1px solid rgba(237,28,46,.35);
    padding: 6px 13px; border-radius: 999px; margin-bottom: 22px; }
.kicker i { font-size: 7px; color: var(--red); animation: blink 1.3s infinite; }
@keyframes blink { 50% { opacity: .2; } }
.brand-mid h1 { font-size: clamp(28px, 3.1vw, 42px); line-height: 1.3; font-weight: 800; letter-spacing: -.5px; margin-bottom: 16px; }
.brand-mid h1 span { color: var(--gold); }
.brand-mid p { color: rgba(255,255,255,.72); font-size: 15px; line-height: 1.8; }

.feats { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; margin-top: 30px; }
.feat { display: flex; align-items: center; gap: 11px; background: rgba(255,255,255,.04); border: 1px solid rgba(255,255,255,.08);
    border-radius: 14px; padding: 12px 14px; font-size: 13px; font-weight: 600; color: rgba(255,255,255,.88); }
.feat i { width: 34px; height: 34px; flex: none; border-radius: 10px; display: grid; place-items: center; font-size: 14px;
    background: rgba(237,28,46,.18); color: #fca5a5; }
.feat:nth-child(even) i { background: rgba(255,217,0,.14); color: var(--gold); }

.brand-foot { font-size: 12.5px; color: rgba(255,255,255,.45); }

/* ---------- right: form ---------- */
.side { flex: 1; position: relative; display: flex; align-items: center; justify-content: center; padding: 32px 24px; background: var(--bg); }
.theme-btn { position: absolute; top: 24px; right: 24px; width: 44px; height: 44px; border-radius: 50%;
    background: var(--panel); border: 1px solid var(--line); color: var(--gold); font-size: 17px; cursor: pointer;
    display: grid; place-items: center; transition: transform .2s, border-color .2s; z-index: 2; }
:root[data-theme="light"] .theme-btn { color: #0f172a; }
.theme-btn:hover { transform: scale(1.06); border-color: var(--red); }
/* home button — sits just left of the light/dark button */
.home-btn { right: 78px; text-decoration: none; }

.box { width: 100%; max-width: 430px; background: var(--panel); border: 1px solid var(--line); border-radius: 26px;
    padding: 40px 36px; box-shadow: var(--shadow); position: relative; overflow: hidden; }
.box::before { content: ''; position: absolute; left: 0; right: 0; top: 0; height: 4px;
    background: linear-gradient(90deg, var(--red), var(--gold)); }

.box-logo { display: none; justify-content: center; margin-bottom: 18px; }
.box-logo img { width: 70px; height: 70px; object-fit: contain; border-radius: 18px; background: #fff; padding: 5px; }

.head { margin-bottom: 26px; }
.head .tag { display: inline-flex; align-items: center; gap: 7px; font-size: 11.5px; font-weight: 700; color: var(--red);
    letter-spacing: .6px; text-transform: uppercase; margin-bottom: 10px; }
.head h2 { font-size: 27px; font-weight: 800; letter-spacing: -.5px; margin-bottom: 6px; }
.head p { color: var(--muted); font-size: 14px; line-height: 1.6; }

.err { display: flex; align-items: flex-start; gap: 10px; background: rgba(239,68,68,.1); border: 1px solid rgba(239,68,68,.28);
    color: #f87171; padding: 13px 14px; border-radius: 12px; margin-bottom: 20px; font-size: 13.5px; font-weight: 500;
    animation: shake .4s ease-in-out; }
.err i { margin-top: 3px; }
@keyframes shake { 25% { transform: translateX(-5px); } 75% { transform: translateX(5px); } }

.fg { margin-bottom: 18px; }
.fg label { display: block; font-size: 12.5px; font-weight: 700; color: var(--muted); margin-bottom: 8px; letter-spacing: .3px; }
.iw { position: relative; }
.iw .ic { position: absolute; left: 16px; top: 50%; transform: translateY(-50%); color: var(--muted); font-size: 15px;
    pointer-events: none; transition: color .2s; }
.iw input, .iw select { width: 100%; padding: 15px 48px 15px 46px; background: var(--input); border: 1.5px solid var(--line);
    border-radius: 14px; color: var(--text); font-size: 15px; font-weight: 500; outline: none;
    transition: border-color .2s, box-shadow .2s, background .2s; }
.iw select { appearance: none; -webkit-appearance: none; cursor: pointer; }
.iw select:invalid { color: var(--muted); }
.iw select option { background: var(--panel); color: var(--text); }
.iw input::placeholder { color: var(--muted); opacity: .7; }
.iw input:focus, .iw select:focus { border-color: var(--red); background: var(--panel-2); box-shadow: 0 0 0 4px rgba(237,28,46,.14); }
.iw input:focus + .ic, .iw select:focus + .ic { color: var(--red); }
.iw .caret { position: absolute; right: 18px; top: 50%; transform: translateY(-50%); color: var(--muted); font-size: 12px; pointer-events: none; }
.eye { position: absolute; right: 8px; top: 50%; transform: translateY(-50%); width: 36px; height: 36px; border: 0;
    background: none; color: var(--muted); font-size: 15px; cursor: pointer; border-radius: 10px; }
.eye:hover { color: var(--text); background: rgba(148,163,184,.12); }

.btn { width: 100%; margin-top: 8px; padding: 15px; border: 0; border-radius: 14px; cursor: pointer;
    background: linear-gradient(135deg, var(--red), var(--red-2)); color: #fff; font-size: 15.5px; font-weight: 700;
    display: flex; align-items: center; justify-content: center; gap: 10px;
    box-shadow: 0 12px 28px rgba(237,28,46,.32); transition: transform .2s, box-shadow .2s, filter .2s; }
.btn:hover { transform: translateY(-2px); filter: brightness(1.06); box-shadow: 0 16px 34px rgba(237,28,46,.4); }
.btn:disabled { opacity: .75; cursor: wait; transform: none; }

.agree { margin-top: 14px; font-size: 12.5px; line-height: 1.7; color: var(--muted); text-align: center; }
.agree a { color: var(--text); font-weight: 600; text-decoration: underline; text-underline-offset: 2px; }
.agree a:hover { color: var(--red); }

.alt { text-align: center; margin-top: 20px; font-size: 13.5px; color: var(--muted); }
.alt a { color: var(--red); font-weight: 700; text-decoration: none; }
.alt a:hover { text-decoration: underline; }
.back { display: block; text-align: center; margin-top: 14px; font-size: 13px; font-weight: 600; color: var(--muted); text-decoration: none; }
.back:hover { color: var(--red); }

@media (max-width: 1100px) {
    .brand { padding: 36px 40px; }
    .feats { grid-template-columns: 1fr; }
}
@media (max-width: 800px) {
    .brand { display: none; }
    .side { padding: 80px 16px 32px;
        background: radial-gradient(circle at 50% -10%, rgba(237,28,46,.22), transparent 55%), var(--bg); }
    .box { padding: 32px 22px; border-radius: 22px; }
    .box-logo { display: flex; }
    .head { text-align: center; }
    .theme-btn { top: 16px; right: 16px; }
    .home-btn { right: 70px; }
}