/* White business theme — shared tokens & base UI */

:root {
    --bg-page: #F5F7FA;
    --bg-surface: #FFFFFF;
    --text-primary: #1A2332;
    --text-secondary: #5B6573;
    --border: #E2E8F0;
    --accent: #1B4F72;
    --accent-hover: #154360;
    --accent-soft: rgba(27, 79, 114, 0.08);
    --accent-shadow: rgba(27, 79, 114, 0.2);
    --success: #1E7A4C;
    --danger: #C0392B;
    --warning: #B7791F;
    --shadow-sm: 0 1px 3px rgba(26, 35, 50, 0.06);
    --shadow-md: 0 4px 16px rgba(26, 35, 50, 0.08);
    --radius: 8px;
    --font-sans: "PingFang SC", "Noto Sans SC", "Microsoft YaHei", sans-serif;
}

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

body {
    font-family: var(--font-sans);
    background: var(--bg-page);
    min-height: 100vh;
    color: var(--text-primary);
}

/* Navbar */
.navbar {
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    padding: 0 2rem;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--accent);
    text-decoration: none;
}

.nav-left {
    display: flex;
    align-items: center;
}

.nav-links {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    transition: background 0.2s ease, color 0.2s ease;
    font-weight: 500;
}

.nav-links a:hover {
    background: var(--accent-soft);
    color: var(--accent);
}

.nav-right {
    margin-left: auto;
    display: flex;
    align-items: center;
}

.avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--accent);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    text-decoration: none;
    font-size: 18px;
    box-shadow: var(--shadow-sm);
    transition: background 0.2s ease, box-shadow 0.2s ease;
}

.avatar:hover {
    background: var(--accent-hover);
    box-shadow: var(--shadow-md);
}

/* Buttons */
.btn,
.cta-button,
.btn-primary {
    display: inline-block;
    background: var(--accent);
    color: #fff;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: background 0.2s ease, box-shadow 0.2s ease;
    box-shadow: var(--shadow-sm);
}

.btn:hover,
.cta-button:hover,
.btn-primary:hover {
    background: var(--accent-hover);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--bg-surface);
    color: var(--accent);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--accent-soft);
    border-color: var(--accent);
}

.btn-success {
    background: var(--success);
    color: #fff;
}

.btn-danger {
    background: var(--danger);
    color: #fff;
}

.btn-warning {
    background: var(--warning);
    color: #fff;
}

/* Form focus */
input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--accent) !important;
    box-shadow: 0 0 0 3px var(--accent-soft) !important;
}

/* Surfaces */
.card,
.feature-card,
.content-card,
.book-card,
.panel {
    background: var(--bg-surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
}

@media (max-width: 768px) {
    .navbar {
        padding: 0 1rem;
    }

    .nav-container {
        flex-direction: row;
        height: 60px;
        padding: 0;
    }

    .nav-links {
        flex-wrap: nowrap;
        gap: 0.75rem;
    }

    .nav-links a {
        padding: 0.4rem 0.6rem;
        font-size: 0.9rem;
    }
}