/* Main Styles */
@import url('reset.css');
@import url('variables.css');

/* Global Reset & Base */
*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    font-family: var(--font-family-base);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text-main);
    background-color: var(--color-bg-body);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: var(--transition-fast);
}

a:hover {
    color: var(--color-primary-light);
}

/* Layout Utilities */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.section {
    padding: var(--spacing-3xl) 0;
    position: relative;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-family-heading);
    color: var(--color-primary-dark);
    line-height: 1.25;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: var(--font-size-4xl);
    font-weight: 800;
}

h2 {
    font-size: var(--font-size-3xl);
    font-weight: 700;
    letter-spacing: -0.5px;
}

h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
}

h4 {
    font-size: var(--font-size-lg);
    font-weight: 600;
}

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

.text-center {
    text-align: center;
}

.text-white {
    color: var(--color-white) !important;
}

.text-primary {
    color: var(--color-primary) !important;
}

/* Components: Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 32px;
    font-weight: 600;
    font-size: var(--font-size-base);
    border-radius: var(--radius-sm);
    transition: var(--transition-base);
    cursor: pointer;
    text-decoration: none;
    border: 2px solid transparent;
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: var(--color-white);
}

.btn-secondary {
    background-color: var(--color-secondary);
    color: var(--color-white);
    box-shadow: var(--shadow-md);
}

.btn-secondary:hover {
    background-color: var(--color-secondary-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: var(--color-white);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--color-white);
    color: var(--color-white);
}

.btn-outline:hover {
    background-color: var(--color-white);
    color: var(--color-primary);
}

/* Components: Cards */
.card {
    background-color: var(--color-bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
    border: 1px solid var(--color-border);
    /* height: 100%; removed to prevent issue in lined-up cards */
    display: flex;
    flex-direction: column;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary-light);
}

.card-title {
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-secondary);
    display: inline-block;
}

/* Utility Grid */
.grid {
    display: grid;
    gap: var(--spacing-xl);
}

.grid-cols-3 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-sidebar {
    grid-template-columns: 1.5fr 1fr;
}

@media (max-width: 768px) {
    .grid-sidebar {
        grid-template-columns: 1fr;
    }
}

/* Header & Nav Overrides */
header {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: var(--transition-base);
}

/* Animations */
.fade-in {
    animation: fadeIn 0.8s ease-out forwards;
    opacity: 0;
    transform: translateY(20px);
}

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

/* Helper Class for Margin */
.mb-lg {
    margin-bottom: var(--spacing-lg);
}

.mb-xl {
    margin-bottom: var(--spacing-xl);
}

/* Footer */
footer {
    background-color: #1a202c;
    /* distinct dark background matching main text color or slightly darker */
    color: var(--color-white);
    padding: var(--spacing-xl) 0;
    margin-top: auto;
    /* Push footer to bottom if content is short */
}

/* Footer ICP 备案信息 */
.footer-icp {
    text-align: center;
    padding-top: var(--spacing-md);
    margin-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-icp p {
    margin: 0;
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.7);
}

.footer-icp a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition-fast);
}

.footer-icp a:hover {
    color: var(--color-white);
    text-decoration: underline;
}