/* ==========================================================================
   style.css — shared shell for all TCM Herb Study pages
   Design tokens, the top navbar, the settings modal, the quiz progress bar,
   and shared layout containers. Linked (root-absolute, because herbquiz is
   also served at /quiz/<slug>) by every public page: index.html,
   quizindex.php, categories.php, herbid.php, herbquiz.php, randomquiz.php.
   Page- and quiz-specific styles live in each page's own <style> block.
   ========================================================================== */

@import "https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css";

/* ---------- design tokens ---------- */
:root {
    --bg: #f4f4f9;
    --card: #ffffff;
    --ink: #2b2b2b;
    --muted: #8a8f98;
    --line: #e6e8ec;
    --header-bg: #ffffff;
    --accent: #007bff;
    --accent-hover: #0056b3;
    /* level tones: bg = pill/card, tile = lighter row background */
    --h1-bg: #d3e3d6;   --h1-tile: #eaf3ec;   --h1-ink: #2f5138;
    --h2-bg: #e6e6c8;   --h2-tile: #f4f4e2;   --h2-ink: #575a29;
    --h3-bg: #d6e2ea;   --h3-tile: #eef4f7;   --h3-ink: #2f5566;
    --rand-bg: #f0e0cb; --rand-tile: #f8efe2; --rand-ink: #7d5426;
}
body.dark-mode {
    --bg: #1c1c1c;
    --card: #2a2a2a;
    --ink: #e8e8e8;
    --muted: #9a9ea6;
    --line: #3a3a3a;
    --header-bg: #2a2a2a;
    --accent: #5b9cf5;
    --accent-hover: #7fb3f7;
    --h1-bg: #2c3a30;   --h1-tile: #24302a;   --h1-ink: #b6d6bd;
    --h2-bg: #3a3a2a;   --h2-tile: #2f2f22;   --h2-ink: #d4d59a;
    --h3-bg: #2b3841;   --h3-tile: #232d33;   --h3-ink: #a8cad9;
    --rand-bg: #3e3324; --rand-tile: #322a1e; --rand-ink: #dcb883;
}

* { box-sizing: border-box; }
body {
    margin: 0;
    background: var(--bg);
    color: var(--ink);
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    -webkit-font-smoothing: antialiased;
    transition: background 0.3s, color 0.3s;
}

/* ---------- top navbar ---------- */
/* sticky on every page, so back/settings stay reachable while scrolling */
.header-bar {
    position: sticky; top: 0; z-index: 100;
    display: flex; align-items: center; justify-content: space-between;
    padding: 6px 18px;
    background: var(--header-bg);
    border-bottom: 1px solid var(--line);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
.header-left { display: flex; align-items: center; gap: 14px; }
.header-right { display: flex; align-items: center; }
.header-bar .logo { height: 36px; width: auto; display: block; }
.header-bar .logo.dark { display: none; }
body.dark-mode .header-bar .logo.light { display: none; }
body.dark-mode .header-bar .logo.dark { display: block; }

.back-btn {
    font-size: 20px; color: var(--ink); text-decoration: none;
    padding: 8px 5px; line-height: 1; transition: color 0.2s;
}
.back-btn:hover { color: var(--muted); }
.settings-btn {
    font-size: 20px; color: var(--ink); cursor: pointer;
    background: none; border: none; padding: 8px 5px; line-height: 1;
    transition: color 0.2s;
}
.settings-btn:hover { color: var(--muted); }

/* ---------- layout ---------- */
.container { max-width: 600px; margin: 0 auto; padding: 30px 18px 60px; }

.welcome { text-align: center; margin-bottom: 22px; }
.welcome h1 { font-size: 1.9rem; font-weight: 700; margin: 0 0 6px; letter-spacing: -0.01em; }
.welcome p { font-size: 1.02rem; color: var(--muted); margin: 0; }

/* white card that wraps a running quiz */
.quiz-container {
    background: var(--card);
    border-radius: 16px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
    padding: 24px;
    max-width: 600px;
    margin: 20px auto;
    transition: background 0.3s;
}

/* ---------- quiz progress bar + timer ---------- */
.progress-header {
    display: flex; justify-content: space-between; align-items: center;
    margin-bottom: 8px;
}
#timer { color: var(--muted); font-size: 0.8rem; margin-left: 10px; }
#progress-counter { font-weight: 600; font-size: 0.8rem; margin-right: 10px; }
.progress-bar-bg {
    background-color: var(--line);
    border-radius: 10px;
    height: 4px;
}
#progress-bar {
    height: 4px;
    background-color: #999;
    width: 0%;
    border-radius: 10px;
    transition: width 0.4s ease-in-out;
}
body.dark-mode #progress-bar { background-color: #90caf9; }

/* ---------- settings modal ---------- */
.modal { display: none; position: fixed; inset: 0; z-index: 200; }
.modal.open { display: block; }
.modal-overlay {
    position: absolute; inset: 0; background: rgba(0,0,0,0.5);
    backdrop-filter: blur(5px); display: flex; justify-content: center; align-items: flex-start;
    padding-top: 90px;
}
.modal-content {
    background: var(--card); color: var(--ink); border-radius: 12px; padding: 22px;
    width: 88%; max-width: 360px; box-shadow: 0 10px 30px rgba(0,0,0,0.25);
}
.modal-content h2 { margin: 0 0 14px; font-size: 1.15rem; }
.toggle-row {
    display: flex; align-items: center; justify-content: space-between;
    margin: 14px 0;
}
.switch { position: relative; width: 42px; height: 22px; flex-shrink: 0; }
.switch input { display: none; }
.slider { position: absolute; inset: 0; background: #ccc; border-radius: 22px; cursor: pointer; transition: 0.3s; }
.slider::before { content: ""; position: absolute; top: 2px; left: 2px; width: 18px; height: 18px; background: #fff; border-radius: 50%; transition: 0.3s; }
.switch input:checked + .slider { background: #58a06a; }
.switch input:checked + .slider::before { transform: translateX(20px); }
.modal-close {
    display: block; margin: 20px auto 0; background: #333; color: #fff; border: none;
    padding: 9px 18px; border-radius: 8px; font-size: 0.95rem; cursor: pointer;
}
body.dark-mode .modal-close { background: #555; }

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* ---------- mobile ---------- */
@media (max-width: 600px) {
    .container { padding: 22px 14px 40px; }
    .welcome h1 { font-size: 1.6rem; }
    .quiz-container { padding: 16px; margin: 10px auto; }

    /* quiz pages (body.quiz-page): the card fills the screen edge-to-edge —
       body goes card-colored, the card itself loses its chrome */
    body.quiz-page { background: var(--card); }
    body.quiz-page .quiz-container {
        background: transparent;
        border-radius: 0;
        box-shadow: none;
        padding: 15px 20px;
        margin: 5px auto 0;
    }
}