/* ============================================================
   Design Tokens — Light (default)
   ============================================================ */
:root {
    --bg-color: #FCF9F2;
    --card-bg: #FFFFFF;
    --text-primary: #5C5453;
    --text-muted: #7f8c8d;
    --primary-color: #A3D2E2;
    --secondary-color: #F8B4C4;
    --accent-color: #F29A94;
    --success-color: #A9DFBF;
    --warning-color: #FCE8A1;
    --border-color: #dcdde1;
    --input-bg: #ffffff;
    --input-border: #ccc;
    --hover-bg: #f1f2f6;
    --progress-bg: #eee;
    --font-family: 'Inter', sans-serif;

    /* Component-specific */
    --navbar-bg: #FFFFFF;
    --navbar-shadow: 0 2px 4px rgba(0,0,0,0.10);
    --card-shadow: 0 8px 24px rgba(0,0,0,0.04);
    --kana-slot-bg: #FAF7F6;
    --kana-slot-border: #D5CACA;
    --kana-pool-bg: #fdfdfd;
    --kana-pool-border: #eee;
    --kana-btn-bg: #ffffff;
    --kana-btn-shadow: 0 3px 8px rgba(0,0,0,0.06);
    --choice-btn-bg: #ffffff;
    --choice-btn-border: #EAE5E5;
    --choice-btn-hover: #FCF9F9;
    --jp-example-bg: #fdfdfd;
    --audio-btn-bg: #F0F7FB;
    --audio-btn-hover: #E2F0F9;
    --grammar-tag-bg: #f0f0f0;
    --grammar-tag-color: #666;
    --grammar-tag-border: #ddd;
    --modal-bg: rgba(0,0,0,0.50);
    --modal-card-bg: #ffffff;
    --admin-edit-bg: #fafafa;
    --admin-edit-border: #ddd;
    --leaderboard-divider: #eee;

    /* Theme-toggle button */
    --theme-btn-bg: #eef7fb;
    --theme-btn-color: #5C5453;
}

/* ============================================================
   Design Tokens — Dark
   ============================================================ */
[data-theme="dark"] {
    --bg-color: #131720;
    --card-bg: #1E2433;
    --text-primary: #D8DCE8;
    --text-muted: #8891A8;
    --primary-color: #6BBCD6;
    --secondary-color: #D98CA4;
    --accent-color: #E07070;
    --success-color: #5CC68A;
    --warning-color: #D4A843;
    --border-color: #2E3549;
    --input-bg: #252B3B;
    --input-border: #3A4255;
    --hover-bg: #2A3245;
    --progress-bg: #2E3549;

    --navbar-bg: #1A2030;
    --navbar-shadow: 0 2px 8px rgba(0,0,0,0.40);
    --card-shadow: 0 8px 28px rgba(0,0,0,0.30);
    --kana-slot-bg: #252B3B;
    --kana-slot-border: #3A4255;
    --kana-pool-bg: #1A2030;
    --kana-pool-border: #2E3549;
    --kana-btn-bg: #252B3B;
    --kana-btn-shadow: 0 3px 8px rgba(0,0,0,0.30);
    --choice-btn-bg: #252B3B;
    --choice-btn-border: #3A4255;
    --choice-btn-hover: #2A3245;
    --jp-example-bg: #1A2030;
    --audio-btn-bg: #1E3A4A;
    --audio-btn-hover: #254D63;
    --grammar-tag-bg: #252B3B;
    --grammar-tag-color: #8891A8;
    --grammar-tag-border: #3A4255;
    --modal-bg: rgba(0,0,0,0.72);
    --modal-card-bg: #1E2433;
    --admin-edit-bg: #1A2030;
    --admin-edit-border: #2E3549;
    --leaderboard-divider: #2E3549;

    --theme-btn-bg: #252B3B;
    --theme-btn-color: #D8DCE8;
}

/* ============================================================
   Reset & Base
   ============================================================ */
* { box-sizing: border-box; margin: 0; padding: 0; }

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-family);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* ============================================================
   Navbar
   ============================================================ */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: var(--navbar-bg);
    box-shadow: var(--navbar-shadow);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
    position: relative;
}

.brand { font-size: 1.5rem; font-weight: 700; color: var(--primary-color); }

/* Navigation controls */
#nav-links, #mobile-menu-btn { display: none !important; }
body.is-logged-in #nav-links { display: flex !important; }

.nav-links a { margin-left: 1rem; color: var(--text-primary); text-decoration: none; font-weight: 600; transition: color 0.2s; }
.nav-links a:hover { color: var(--primary-color); }

/* ============================================================
   Theme Toggle Button
   ============================================================ */
#theme-toggle-btn {
    background: var(--theme-btn-bg);
    border: 1px solid var(--border-color);
    color: var(--theme-btn-color);
    border-radius: 20px;
    padding: 4px 12px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 5px;
    white-space: nowrap;
    font-family: var(--font-family);
}
#theme-toggle-btn:hover {
    background: var(--hover-bg);
    transform: translateY(-1px);
}

/* Select dropdowns — both lang and level respond to theme */
#lang-select,
#user-level-select {
    background: var(--input-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 4px 8px;
    font-size: 0.9rem;
    cursor: pointer;
    outline: none;
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}
#user-level-select option,
#user-level-select optgroup {
    background: var(--input-bg);
    color: var(--text-primary);
}

/* ============================================================
   Container & Layout
   ============================================================ */
.container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 1rem;
}

.view { display: none; }
.view.active { display: block; animation: fadeIn 0.3s; }

@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* ============================================================
   Cards
   ============================================================ */
.auth-card, .stat-card, .flashcard {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    margin-bottom: 1.5rem;
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

.auth-card { max-width: 400px; margin: 0 auto; text-align: center; }
.auth-card input {
    width: 100%;
    padding: 0.8rem;
    margin: 0.5rem 0;
    border: 1px solid var(--input-border);
    border-radius: 6px;
    background: var(--input-bg);
    color: var(--text-primary);
    transition: background-color 0.3s, border-color 0.3s, color 0.3s;
}
.auth-card input::placeholder { color: var(--text-muted); }

.auth-buttons { display: flex; gap: 1rem; margin-top: 1rem; }

/* ============================================================
   Buttons
   ============================================================ */
.btn {
    padding: 0.5rem 0.8rem;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    flex: 1;
    transition: all 0.2s;
    font-family: var(--font-family);
}

.btn.primary { background: var(--primary-color); color: #fff; box-shadow: 0 4px 10px rgba(163,210,226,0.3); }
.btn.primary:hover { opacity: 0.9; transform: translateY(-2px); }

/* Dark mode: primary button — deep slate-blue instead of bright macaron */
[data-theme="dark"] .btn.primary {
    background: #3A7A96;
    box-shadow: 0 4px 10px rgba(58,122,150,0.35);
}
[data-theme="dark"] .btn.primary:hover {
    background: #4A8FAD;
    opacity: 1;
}

.btn.secondary {
    background: var(--card-bg);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}
.btn.secondary:hover { background: var(--hover-bg); }

/* Dark mode: secondary button border should be visible */
[data-theme="dark"] .btn.secondary {
    background: var(--card-bg);
    border-color: var(--border-color);
}

.btn.warning { background: var(--warning-color); color: #5C5453; }
/* Dark mode: muted amber instead of bright macaron yellow */
[data-theme="dark"] .btn.warning {
    background: #8A6C28;
    color: #F0D8A0;
}

.btn.huge { font-size: 1.1rem; padding: 1rem; margin-top: 1rem; display: block; width: 100%; border-radius: 12px; }

.error-msg { color: var(--accent-color); margin-top: 1rem; font-size: 0.9rem; }

/* ============================================================
   Dashboard Stats
   ============================================================ */
.stats-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 2rem; }

.stat-card.urgent {
    background: linear-gradient(135deg, #F8B4C4 0%, #FAD0D9 100%);
    color: #5C5453;
}
[data-theme="dark"] .stat-card.urgent {
    background: linear-gradient(135deg, #6B2D3D 0%, #4E2030 100%);
    color: #E8C0C8;
}
.stat-card.urgent h1 { font-size: 3rem; margin: 0; color: #D56C81; text-shadow: none; }
.stat-card.urgent p { color: #D56C81; font-weight: bold; }
[data-theme="dark"] .stat-card.urgent h1 { color: #E8A0A8; }
[data-theme="dark"] .stat-card.urgent p { color: #E8A0A8; }

/* Progress Bar */
.progress-bar {
    background: var(--progress-bg);
    height: 12px;
    border-radius: 6px;
    overflow: hidden;
    margin: 1rem 0;
    transition: background-color 0.3s;
}
.progress-fill { background: var(--success-color); height: 100%; transition: width 0.5s; }

/* ============================================================
   Flashcard
   ============================================================ */
.flashcard { justify-content: center; text-align: center; display: flex; flex-direction: column; position: relative; }
.flashcard h1 { font-size: 4rem; margin-bottom: 0px; line-height: 1; }
.ruby-text { font-size: 1.5rem; color: var(--text-muted); margin-bottom: 0.5rem; }
.meaning { font-size: 1.2rem; font-weight: bold; margin-bottom: 1.5rem; color: var(--primary-color); }

.jp-example {
    font-size: 1.1rem;
    text-align: left;
    background: var(--jp-example-bg);
    padding: 1rem;
    border-left: 4px solid var(--primary-color);
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    transition: background-color 0.3s;
}
.cn-example { font-size: 1rem; color: var(--text-muted); text-align: left; padding-left: 1rem; }

.hidden { display: none !important; }
.study-controls { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; }

.kana-input {
    width: 100%; padding: 1rem; font-size: 1.5rem; text-align: center;
    border: 2px solid var(--primary-color); border-radius: 8px; margin: 1rem 0;
    background: var(--input-bg); color: var(--text-primary);
    transition: background-color 0.3s, color 0.3s;
}

/* ============================================================
   Kana Tiles
   ============================================================ */
.kana-slots { display: flex; justify-content: center; gap: 0.5rem; margin-bottom: 1.5rem; flex-wrap: wrap; }

.kana-slot {
    width: 40px; height: 50px;
    border: 2px dashed var(--kana-slot-border);
    border-radius: 10px;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.5rem; font-weight: bold;
    background: var(--kana-slot-bg);
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s;
}
.kana-slot.filled { border-style: solid; border-color: var(--primary-color); background: var(--card-bg); box-shadow: 0 4px 10px rgba(0,0,0,0.08); }
.kana-slot.wrong { border-color: var(--accent-color); background: rgba(226,112,112,0.15); animation: shake 0.3s; }
.kana-slot.right { border-color: var(--success-color); background: rgba(92,198,138,0.15); }

.kana-pool {
    display: flex; justify-content: center; gap: 0.5rem; flex-wrap: wrap;
    margin: 0 auto 2rem auto;
    background: var(--kana-pool-bg);
    padding: 1rem; border-radius: 8px;
    border: 1px solid var(--kana-pool-border);
    max-width: 340px;
    transition: background-color 0.3s;
}

.kana-btn {
    width: 45px; height: 45px;
    border: none; border-radius: 10px;
    background: var(--kana-btn-bg);
    box-shadow: var(--kana-btn-shadow);
    font-size: 1.2rem; cursor: pointer;
    transition: transform 0.1s, background 0.2s;
    display: flex; align-items: center; justify-content: center;
    color: var(--text-primary);
}
.kana-btn:hover { background: var(--hover-bg); transform: translateY(-2px); }
.kana-btn.used { opacity: 0; pointer-events: none; transform: scale(0.8); }

/* ============================================================
   Audio Button
   ============================================================ */
.audio-btn {
    background: var(--audio-btn-bg);
    color: var(--primary-color);
    border: none; border-radius: 50%;
    width: 40px; height: 40px;
    font-size: 1.2rem; cursor: pointer;
    display: inline-flex; align-items: center; justify-content: center;
    margin-right: 0.5rem;
    transition: transform 0.2s, background-color 0.3s;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}
.audio-btn:hover { transform: scale(1.1); background: var(--audio-btn-hover); }
.audio-btn.huge { width: 80px; height: 80px; font-size: 2.5rem; margin: 2rem auto; display: block; animation: pulse 2s infinite; }

@keyframes pulse {
    0%   { box-shadow: 0 0 0 0 rgba(107, 188, 214, 0.4); }
    70%  { box-shadow: 0 0 0 20px rgba(107, 188, 214, 0); }
    100% { box-shadow: 0 0 0 0 rgba(107, 188, 214, 0); }
}

/* ============================================================
   Multiple Choice
   ============================================================ */
.multiple-choice { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; margin-top: 1rem; }

.choice-btn {
    background: var(--choice-btn-bg);
    border: 2px solid var(--choice-btn-border);
    padding: 1rem; font-size: 1.1rem;
    border-radius: 12px; cursor: pointer;
    transition: 0.2s;
    color: var(--text-primary);
    font-family: var(--font-family);
}
.choice-btn:hover { background: var(--choice-btn-hover); border-color: var(--primary-color); }
.choice-btn.wrong { background: var(--accent-color); color: white; border-color: var(--accent-color); animation: shake 0.3s; }
.choice-btn.right { background: var(--success-color); color: #1a1a1a; border-color: var(--success-color); }

@keyframes shake {
    0%   { transform: translateX(0); }
    25%  { transform: translateX(-5px); }
    50%  { transform: translateX(5px); }
    75%  { transform: translateX(-5px); }
    100% { transform: translateX(0); }
}

/* ============================================================
   Study Header / Badge
   ============================================================ */
.study-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 1rem; }
.badge { background: var(--primary-color); color: white; padding: 4px 12px; border-radius: 20px; font-weight: bold; font-size: 0.8rem; }

/* ============================================================
   Admin Panel
   ============================================================ */
#admin-edit-panel {
    background: var(--admin-edit-bg) !important;
    border-color: var(--admin-edit-border) !important;
    color: var(--text-primary);
    transition: background-color 0.3s;
}
#admin-edit-panel input,
#admin-edit-panel textarea {
    background: var(--input-bg);
    color: var(--text-primary);
    border: 1px solid var(--input-border);
    border-radius: 4px;
    padding: 0.5rem;
    width: 100%;
    margin-bottom: 0.5rem;
    font-family: var(--font-family);
    transition: background-color 0.3s, color 0.3s;
}

/* Admin search fields */
#admin-search {
    background: var(--input-bg);
    color: var(--text-primary);
    border: 1px solid var(--input-border);
    padding: 0.5rem;
    border-radius: 6px;
    flex: 1;
    font-family: var(--font-family);
    transition: background-color 0.3s, color 0.3s;
}

/* ============================================================
   Modals
   ============================================================ */
.modal-inner {
    background: var(--modal-card-bg) !important;
    color: var(--text-primary);
    transition: background-color 0.3s;
}

/* ============================================================
   Leaderboard
   ============================================================ */
.leaderboard-row-divider { border-bottom: 1px solid var(--leaderboard-divider); }

/* ============================================================
   Profile/Register form labels
   ============================================================ */
.profile-label { color: var(--text-muted) !important; }
#profile-nickname, #profile-password, #profile-confirm-password,
#login-email, #login-password,
#reg-email, #reg-password, #reg-confirm-password, #reg-nickname,
#forgot-email {
    background: var(--input-bg);
    color: var(--text-primary);
    border-color: var(--input-border);
    transition: background-color 0.3s, color 0.3s, border-color 0.3s;
}

/* ============================================================
   Admin search results hover
   ============================================================ */
.admin-result-row { background: transparent; transition: background 0.2s; }
.admin-result-row:hover { background: var(--hover-bg) !important; }

/* ============================================================
   Responsive / Mobile
   ============================================================ */
@media (max-width: 600px) {
    /* Menu collapses to Hamburger */
    body.is-logged-in #mobile-menu-btn { display: block !important; }
    body.is-logged-in #nav-links {
        display: none !important;
        flex-direction: column;
        position: absolute;
        top: 60px;
        right: 0;
        background: var(--navbar-bg);
        width: 100%;
        box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        padding: 1rem;
        z-index: 100;
    }
    body.is-logged-in #nav-links.mobile-open { display: flex !important; }
    .nav-links a { margin: 0.8rem 0; width: 100%; text-align: center; font-size: 1.1rem; }

    /* Narrow borders for maximum screen usage */
    .navbar { padding: 1rem; }
    .container { padding: 0.5rem; margin: 0.5rem auto; }
    .auth-card, .stat-card, .flashcard { padding: 1rem; border-radius: 12px; margin-bottom: 1rem; }
    .stats-cards { grid-template-columns: 1fr; gap: 1rem; }

    .flashcard h1 { font-size: 3rem; }
    .btn { padding: 0.6rem 1rem; font-size: 0.95rem; }

    #theme-toggle-btn { font-size: 0.75rem; padding: 4px 8px; }
}