/* Core page and player styling for the video lesson layout. */
/* TODO: change colour scheme as needed */
:root {
    --bg: #f4f8ff;
    --panel: #e6f0ff;
    --accent: #4ca3ff;
    --accent-2: #76c5ff;
    --text: #0f1b2e;
    --muted: #4e6485;
    --shadow: 0 10px 30px rgba(34, 66, 120, 0.18);
    --radius: 18px;
    --glass: rgba(255, 255, 255, 0.7);
}

* {
    box-sizing: border-box;
}

/* Media query for accessibility */
@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}

/* Global icon centering helper */
.fa {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    vertical-align: middle;
    line-height: 1;
}

/* Media query for accessibility */
@media (prefers-reduced-motion: no-preference) {
    html {
        scroll-behavior: smooth;
    }
}

.fa {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    vertical-align: middle;
    line-height: 1;
}

/* Page layout & background */
body {
    margin: 0;
    min-height: 100vh;
    display: grid;
    place-items: center;
    padding-top: 170px;
    padding-bottom: 48px;
    background: radial-gradient(circle at 20% 20%, #f0f6ff, #d8e8ff 45%), radial-gradient(circle at 80% 60%, #f2f9ff, #dfeeff 55%), #f4f8ff;
    color: var(--text);
    font-family: "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    position: relative;
}

.breadcrumb {
    position: absolute;
    top: 16px;
    left: 50%;
    transform: translateX(-50%);
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 8px 14px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.9);
    color: #0f1b2e;
    font-weight: 600;
    font-size: 14px;
    box-shadow: 0 6px 16px rgba(76, 163, 255, 0.12);
    border: 1px solid rgba(15, 27, 46, 0.08);
}

.breadcrumb a {
    color: inherit;
    text-decoration: none;
    padding: 2px 4px;
    border-radius: 8px;
    transition: background-color 0.16s ease, color 0.16s ease;
}

.breadcrumb a:hover {
    background: rgba(76, 163, 255, 0.12);
    color: #0c5ba8;
}

.breadcrumb a:active {
    transform: translateY(1px);
}

.breadcrumb .crumb-sep {
    color: var(--muted);
    font-weight: 500;
}

/* Player container sizing and fullscreen adjustments */
.player {
    width: min(960px, 96vw);
    background: var(--panel);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.04);
    position: relative;
}

.video-shell {
    position: relative;
    background: #d9e7ff;
    aspect-ratio: 16 / 9;
    overflow: hidden;
}

.video {
    width: 100%;
    display: block;
    height: 100%;
    object-fit: contain;
    background: #000;
}

.player:fullscreen {
    width: 100vw;
    height: 100vh;
    border-radius: 0;
    display: flex;
    flex-direction: column;
}

.player:fullscreen .video-shell {
    height: 100%;
    flex: 1;
}

.player:fullscreen video {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.player:fullscreen .controls {
    position: absolute;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 2;
    padding: 8px 12px 10px;
    background: linear-gradient(180deg, rgba(230, 240, 255, 0.75), rgba(214, 231, 255, 0.78));
}

.controls {
    padding: 14px 18px 16px;
    background: linear-gradient(180deg, rgba(230, 240, 255, 0.92), rgba(214, 231, 255, 0.95));
    backdrop-filter: blur(12px);
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.row {
    display: flex;
    align-items: center;
    gap: 10px;
}

.row + .row {
    margin-top: 10px;
}

.row.top {
    font-size: 14px;
    color: var(--muted);
}

.page-back-btn {
    position: absolute;
    top: 18px;
    left: 18px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    height: 36px;
    border-radius: 12px;
    border: 1px solid rgba(15, 27, 46, 0.08);
    background: var(--glass);
    color: var(--text);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.16s ease;
    box-shadow: 0 6px 16px rgba(76, 163, 255, 0.12);
}

.page-title {
    position: absolute;
    top: 120px;
    left: 50%;
    transform: translateX(-50%);
    margin: 0 0 44px 0;
    font-size: 36px;
    color: #0f1b2e;
    font-weight: 800;
    letter-spacing: -0.4px;
}

.footer-nav {
    width: min(720px, 94vw);
    margin: 32px auto 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
}

.nav-btn {
    background: linear-gradient(135deg, #67b7ff, #a8d8ff);
    color: #0f1b2e;
    border: 1px solid rgba(15, 27, 46, 0.08);
    border-radius: 12px;
    padding: 10px 16px;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 10px 24px rgba(103, 183, 255, 0.26);
    transition: transform 0.14s ease, box-shadow 0.14s ease, filter 0.14s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.nav-btn:hover {
    box-shadow: 0 12px 28px rgba(103, 183, 255, 0.30);
    filter: brightness(1.02);
}

.nav-btn:active {
    transform: translateY(1px) scale(0.99);
}

.nav-btn i {
    width: 16px;
    height: 16px;
}

.resources {
    flex: 1;
    min-width: 180px;
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.resources-title {
    font-size: 14px;
    font-weight: 700;
    color: #0f1b2e;
}

.player {
    margin-top: 64px;
}

.resources-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.resource-btn {
    padding: 12px 16px;
    border-radius: 14px;
    border: 1px solid rgba(15, 27, 46, 0.08);
    color: #ffffff;
    font-weight: 700;
    font-size: 15px;
    cursor: pointer;
    box-shadow: 0 10px 22px rgba(0, 0, 0, 0.08);
    transition: transform 0.14s ease, box-shadow 0.14s ease, filter 0.14s ease;
    min-width: 240px;
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: 12px;
}

.resource-btn.quiz {
    background: linear-gradient(135deg, #0fb579, #10a96f);
}

.resource-btn.flash {
    background: linear-gradient(135deg, #0eb5c2, #0da6b0);
}

.resource-btn:hover {
    filter: brightness(1.02);
    box-shadow: 0 12px 26px rgba(0, 0, 0, 0.12);
}

.resource-btn:active {
    transform: translateY(1px) scale(0.99);
}

.resource-icon {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.12);
    display: grid;
    place-items: center;
    border: 1px solid rgba(255, 255, 255, 0.18);
}

.resource-icon i {
    color: #ffffff;
    font-size: 20px;
    line-height: 1;
}

.resource-label {
    text-align: left;
}

.resource-arrow {
    color: rgba(255, 255, 255, 0.78);
    font-size: 13px;
    line-height: 1;
    font-weight: 500;
}

@media (max-width: 640px) {
    body {
        padding-top: 140px;
        padding-bottom: 36px;
    }
    .player {
        width: min(420px, 92vw);
        margin: 64px auto 0;
    }
    .breadcrumb {
        top: 12px;
        gap: 8px;
        padding: 6px 12px;
        font-size: 13px;
    }
    .page-title {
        top: 96px;
        margin: 0 0 32px 0;
        font-size: 30px;
    }
    .footer-nav {
        width: min(720px, 94vw);
        margin: 24px auto 24px;
        padding: 0 12px;
        gap: 10px;
        justify-content: space-between;
        flex-direction: column;
    }
    .nav-btn {
        flex: 1;
        text-align: center;
        padding: 10px 12px;
        font-size: 14px;
    }
    .controls {
        padding: 12px 12px 14px;
    }
    .row {
        flex-wrap: wrap;
        gap: 8px;
    }
    .row.mid {
        align-items: center;
    }
    .row.mid .time {
        order: 1;
    }
    .row.mid .progress {
        order: 3;
        width: 100%;
        margin-top: 6px;
    }
    .row.mid button {
        order: 0;
    }
    .row.bottom {
        flex-wrap: wrap;
        gap: 8px;
    }
    .volume-group {
        width: 100%;
        justify-content: flex-start;
    }
    .volume {
        width: 120px;
    }
    .icon-btn {
        width: 38px;
        height: 38px;
        border-radius: 10px;
    }
    .resources {
        order: -1;
        width: 100%;
    }
    .resources-actions {
        width: 100%;
    }
    /* Portrait video for mobile screens */
    .video-shell {
        aspect-ratio: auto;
        height: auto;
        max-height: none;
        margin: 0 auto;
    }
    .video {
        width: 100%;
        height: auto;
        object-fit: contain;
    }
    .video-shell .overlay {
        inset: 0;
        width: 100%;
        height: 100%;
    }
}

@media (max-width: 480px) {
    body {
        padding-top: 240px;
    }
    .page-back-btn {
        top: 10px;
        left: 12px;
        z-index: 6;
    }
    .breadcrumb {
        top: 58px;
        max-width: calc(100% - 32px);
        left: 50%;
        transform: translateX(-50%);
        justify-content: center;
        text-align: center;
        flex-wrap: wrap;
        gap: 6px;
        padding: 8px 12px;
    }
    .page-title {
        top: 170px;
        font-size: 26px;
        width: calc(100% - 32px);
        text-align: center;
    }
}

.page-back-btn i {
    width: 16px;
    height: 16px;
}

.page-back-btn:hover {
    border-color: rgba(76, 163, 255, 0.8);
    box-shadow: 0 10px 20px rgba(76, 163, 255, 0.16);
    background: rgba(255, 255, 255, 0.9);
}

.page-back-btn:active {
    transform: translateY(1px) scale(0.99);
}

.title {
    font-weight: 600;
    color: var(--text);
}

.spacer {
    flex: 1;
}

.icon-btn {
    width: 42px;
    height: 42px;
    border-radius: 12px;
    border: 1px solid rgba(15, 27, 46, 0.08);
    background: var(--glass);
    display: grid;
    place-items: center;
    cursor: pointer;
    transition: all 0.16s ease;
    color: var(--text);
    padding: 0;
}

.icon-btn i {
    width: 22px;
    height: 22px;
    color: var(--text);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    line-height: 1;
}

#fullscreen {
    position: relative;
}

#fullscreen i {
    width: 22px;
    height: 22px;
    position: absolute;
    inset: 0;
    margin: auto;
}

.icon-btn:hover {
    border-color: rgba(76, 163, 255, 0.8);
    box-shadow: 0 10px 24px rgba(76, 163, 255, 0.18);
}

.icon-btn:active {
    transform: translateY(1px) scale(0.98);
}

.icon-btn .pause,
.icon-btn .muted,
.icon-btn .exit {
    display: none;
}

.video-shell .overlay {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    display: grid;
    place-items: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
    background: radial-gradient(circle, rgba(0, 0, 0, 0.3), transparent 50%);
}

.video-shell.paused .overlay {
    opacity: 1;
    pointer-events: auto;
}

.icon-btn.center {
    width: 72px;
    height: 72px;
    border-radius: 22px;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    box-shadow: 0 18px 40px rgba(63, 169, 245, 0.35);
    border: none;
}

.icon-btn.center i {
    width: 32px;
    height: 32px;
    color: #0b1623;
    line-height: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.page-back-btn i,
.nav-btn i {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

.time {
    min-width: 110px;
    color: var(--muted);
    font-variant-numeric: tabular-nums;
    display: flex;
    align-items: center;
    gap: 4px;
}

.divider {
    color: rgba(15, 27, 46, 0.45);
}

.slider {
    appearance: none;
    height: 10px;
    border-radius: 999px;
    background: #d1e4ff;
    outline: none;
    cursor: pointer;
    transition: box-shadow 0.16s ease, border 0.16s ease;
    border: 1px solid rgba(15, 27, 46, 0.14);
    box-shadow: inset 0 1px 2px rgba(15, 27, 46, 0.12);
}

.slider::-webkit-slider-thumb {
    appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    box-shadow: 0 6px 14px rgba(76, 163, 255, 0.35);
    border: 2px solid #f4f8ff;
}

.slider:active::-webkit-slider-thumb {
    transform: scale(1.04);
}

.progress {
    flex: 1;
    height: 10px;
    background: linear-gradient(90deg, var(--accent) var(--progress, 0%), #d1e4ff var(--progress, 0%));
    box-shadow: 0 2px 8px rgba(76, 163, 255, 0.18);
}

.volume-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

.volume {
    width: 110px;
}

.speed-group {
    display: flex;
    align-items: center;
    gap: 6px;
    color: var(--muted);
    font-size: 14px;
}

.speed-group select {
    background: #f9fcff;
    color: #0f1b2e;
    border: 1px solid rgba(76, 163, 255, 0.5);
    border-radius: 10px;
    padding: 6px 10px;
    outline: none;
    box-shadow: inset 0 0 0 1px rgba(15, 27, 46, 0.04);
    transition: border-color 0.16s ease, box-shadow 0.16s ease, background-color 0.16s ease;
}

.speed-group select:hover,
.speed-group select:focus {
    border-color: var(--accent-2);
    box-shadow: 0 0 0 3px rgba(76, 163, 255, 0.25);
    background: #ffffff;
}

.row.bottom {
    margin-top: 6px;
}

.video-shell:hover .overlay {
    opacity: 0.35;
}

.video-shell.paused:hover .overlay {
    opacity: 1;
}

.hidden {
    display: none !important;
}

.player.controls-hidden {
    cursor: none;
}

.player.controls-hidden .controls {
    opacity: 0;
    pointer-events: none;
    transform: translateY(8px);
}