/* =============================================
   MathLearn - CSS Variables & Global Styles
   ============================================= */

@import url('https://fonts.googleapis.com/css2?family=Space+Mono:wght@400;700&family=Crimson+Pro:wght@300;600&display=swap');

:root {
    --primary: #2D3250;
    --secondary: #424769;
    --accent: #7077A1;
    --light: #F6B17A;
    --bg: #1a1d2e;
    --text: #e8e9f3;
    --border: rgba(255, 255, 255, 0.1);
    --card-bg: rgba(45, 50, 80, 0.7);
    --input-bg: rgba(26, 29, 46, 0.6);
    --hover-shadow: rgba(246, 177, 122, 0.2);
    --float-color: rgba(240, 177, 122, 0.1);
    --shadow-empty: rgba(0, 0, 0, 0.2);
}

[data-theme="light"] {
    --primary: #f5f7fa;
    --secondary: #ffffff;
    --accent: #5a67d8;
    --light: #ed8936;
    --bg: #edf2f7;
    --text: #2d3748;
    --border: #cbd5e0;
    --card-bg: #ffffff;
    --input-bg: #f7fafc;
    --hover-shadow: rgba(0, 0, 0, 0.1);
    --float-color: rgba(237, 137, 54, 0.1);
    --shadow-empty: rgba(0, 0, 0, 0.06);
}

[data-theme="dark"] {
    --primary: #2D3250;
    --secondary: #424769;
    --accent: #7077A1;
    --light: #F6B17A;
    --bg: #1a1d2e;
    --text: #e8e9f3;
    --border: rgba(255, 255, 255, 0.1);
    --card-bg: rgba(45, 50, 80, 0.7);
    --input-bg: rgba(26, 29, 46, 0.6);
    --hover-shadow: rgba(246, 177, 122, 0.2);
    --float-color: rgba(240, 177, 122, 0.1);
    --shadow-empty: rgba(0, 0, 0, 0.2);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Crimson Pro', serif;
    color: var(--text);
    transition: background 0.3s ease, color 0.3s ease;
}

/* ---- Navbar ---- */
.navbar {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    padding: 18px 40px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.15);
}

.navbar .brand {
    font-family: 'Space Mono', monospace;
    font-size: 1.8em;
    font-weight: 700;
    color: var(--light);
    letter-spacing: -1px;
    text-decoration: none;
}

.navbar .nav-links {
    display: flex;
    gap: 28px;
    align-items: center;
}

.navbar .nav-links a {
    color: var(--text);
    text-decoration: none;
    font-size: 1em;
    letter-spacing: 1px;
    transition: color 0.3s;
}

.navbar .nav-links a:hover { color: var(--light); }

.navbar .nav-links a.active { color: var(--light); font-weight: 600; }

.navbar .logout {
    background: rgba(255, 82, 82, 0.25);
    padding: 7px 18px;
    border-radius: 8px;
    border: 1px solid rgba(255, 82, 82, 0.4);
}

.navbar .logout:hover { background: rgba(255, 82, 82, 0.45); }

/* ---- Theme Toggle ---- */
.theme-toggle {
    background: var(--card-bg);
    border: 2px solid var(--border);
    border-radius: 50px;
    padding: 8px 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.3s ease;
    font-family: 'Space Mono', monospace;
    font-size: 0.85em;
    color: var(--text);
}

.theme-toggle:hover {
    border-color: var(--light);
    transform: translateY(-2px);
}

/* ---- Buttons ---- */
.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 12px;
    font-size: 1em;
    font-weight: 700;
    font-family: 'Space Mono', monospace;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: linear-gradient(135deg, var(--light) 0%, #e89f6a 100%);
    color: #2d3748;
    box-shadow: 0 6px 18px rgba(246, 177, 122, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(246, 177, 122, 0.4);
}

.btn-secondary {
    background: transparent;
    color: var(--accent);
    border: 2px solid var(--accent);
}

.btn-secondary:hover {
    background: var(--accent);
    color: #fff;
    transform: translateY(-2px);
}

.btn-full { width: 100%; text-align: center; }

/* ---- Form Elements ---- */
.form-group { margin-bottom: 20px; }

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--light);
    font-weight: 600;
    font-size: 0.9em;
    letter-spacing: 1px;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 13px 18px;
    border: 2px solid var(--border);
    border-radius: 12px;
    background: var(--input-bg);
    color: var(--text);
    font-size: 0.95em;
    font-family: 'Crimson Pro', serif;
    transition: all 0.3s ease;
    box-shadow: 0 2px 6px var(--shadow-empty);
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--light);
    box-shadow: 0 0 0 4px rgba(246, 177, 122, 0.12);
}

.form-group select { cursor: pointer; }

/* ---- Alerts ---- */
.alert {
    padding: 12px 18px;
    border-radius: 10px;
    margin-bottom: 20px;
    font-size: 0.92em;
    text-align: center;
}

.alert-error {
    background: rgba(255, 82, 82, 0.15);
    border: 1px solid rgba(255, 82, 82, 0.4);
    color: #ef4444;
}

.alert-success {
    background: rgba(82, 255, 168, 0.15);
    border: 1px solid rgba(82, 255, 168, 0.4);
    color: #10b981;
}

/* ---- Card ---- */
.card {
    background: var(--card-bg);
    backdrop-filter: blur(20px);
    border-radius: 20px;
    padding: 35px;
    border: 1px solid var(--border);
    box-shadow: 0 4px 20px var(--hover-shadow);
    margin-bottom: 28px;
}

/* ---- Section Title ---- */
.section-title {
    font-family: 'Space Mono', monospace;
    font-size: 1.7em;
    color: var(--light);
    margin: 45px 0 22px 0;
    padding-bottom: 14px;
    border-bottom: 2px solid var(--border);
}

/* ---- Animations ---- */
@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateY(-20px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-8px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes float {
    0%,  100% { transform: translate(0, 0) rotate(0deg); }
    25%        { transform: translate(30px, -30px) rotate(90deg); }
    50%        { transform: translate(-20px, 20px) rotate(180deg); }
    75%        { transform: translate(20px, 30px) rotate(270deg); }
}

/* ---- Responsive ---- */
@media (max-width: 768px) {
    .navbar { padding: 14px 18px; flex-direction: column; gap: 12px; }
    .navbar .nav-links { flex-wrap: wrap; justify-content: center; gap: 14px; }
    .card { padding: 22px 18px; }
}