/* CSS Variables */
:root {
    --color-bg: #1A1A2E;
    --color-card: #16213E;
    --color-card-hover: #1F2B47;
    --color-primary: #2ECC71;
    --color-primary-dark: #27AE60;
    --color-text: #FFFFFF;
    --color-text-muted: #8892A6;
    --color-border: #2A3F5F;
    --color-pending: #E74C3C;
    --transition-speed: 0.3s;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    min-height: 100vh;
    line-height: 1.5;
}

/* Header */
.header {
    background: linear-gradient(180deg, var(--color-card) 0%, var(--color-bg) 100%);
    padding: 2rem 1rem;
    text-align: center;
    border-bottom: 1px solid var(--color-border);
}

.header-content {
    max-width: 600px;
    margin: 0 auto;
}

.header h1 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.subtitle {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    margin-bottom: 1.5rem;
}

/* Progress Bar */
.progress-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    max-width: 400px;
    margin: 0 auto;
}

.progress-bar {
    flex: 1;
    height: 12px;
    background: var(--color-border);
    border-radius: 6px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    border-radius: 6px;
    transition: width 0.5s ease-out;
    width: 0;
}

.progress-text {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--color-primary);
    min-width: 60px;
    text-align: right;
}

/* Main */
.main {
    padding: 1.5rem 1rem;
    max-width: 1400px;
    margin: 0 auto;
}

/* Filters */
.filters {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--color-border);
    background: var(--color-card);
    color: var(--color-text-muted);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all var(--transition-speed);
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

.filter-btn:hover {
    background: var(--color-card-hover);
    color: var(--color-text);
}

.filter-btn.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: var(--color-bg);
    font-weight: 600;
}

/* Grid */
.grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

/* Cards */
.card {
    background: var(--color-card);
    border-radius: 12px;
    padding: 1.25rem;
    border: 1px solid var(--color-border);
    transition: all var(--transition-speed);
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-2px);
    background: var(--color-card-hover);
}

.card.completed {
    border-color: var(--color-primary);
}

.card.completed::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--color-primary);
}

.card-number {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.card-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--color-text);
}

.card-description {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-bottom: 0.75rem;
    line-height: 1.4;
}

.card-category {
    display: inline-block;
    font-size: 0.75rem;
    padding: 0.25rem 0.5rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 4px;
    color: var(--color-text-muted);
}

.card-button {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.6rem 1.5rem;
    background: var(--color-primary);
    color: var(--color-bg);
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    font-size: 0.85rem;
    transition: background var(--transition-speed);
    min-height: 44px;
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
}

.card-button:hover {
    background: var(--color-primary-dark);
}

.card-status {
    display: inline-block;
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--color-text-muted);
    font-style: italic;
}

/* Footer */
.footer {
    padding: 2rem 1rem;
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.85rem;
    border-top: 1px solid var(--color-border);
    margin-top: 2rem;
}

/* Responsive */
@media (min-width: 480px) {
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 768px) {
    .header h1 {
        font-size: 2rem;
    }

    .grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .main {
        padding: 2rem;
    }
}

@media (min-width: 1024px) {
    .grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Hidden utility */
.hidden {
    display: none !important;
}