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

:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --success: #10b981;
    --error: #ef4444;
    --bg: #f8fafc;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #0f172a;
        --card-bg: #1e293b;
        --text: #f1f5f9;
        --text-light: #94a3b8;
        --border: #334155;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem 1rem;
    flex: 1;
}

/* Header */
.header {
    text-align: center;
    margin-bottom: 3rem;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, var(--primary), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-light);
    font-size: 1.1rem;
}

/* Form Section */
.form-section {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.input-group {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.input-group input[type="url"] {
    flex: 1;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1rem;
    background: var(--bg);
    color: var(--text);
    transition: border-color 0.2s;
}

.input-group input[type="url"]:focus {
    outline: none;
    border-color: var(--primary);
}

.input-group button {
    padding: 0.875rem 2rem;
    background: var(--primary);
    color: white;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}

.input-group button:hover {
    background: var(--primary-dark);
}

.input-group button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.custom-code-group {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.custom-code-group label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    color: var(--text-light);
}

.custom-code-group input[type="text"] {
    padding: 0.5rem 0.75rem;
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    font-size: 0.9rem;
    background: var(--bg);
    color: var(--text);
    flex: 1;
    min-width: 200px;
}

.custom-code-group input[type="text"]:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.custom-code-group input[type="text"]:focus {
    outline: none;
    border-color: var(--primary);
}

/* Result Section */
.result-section {
    animation: slideIn 0.3s ease-out;
}

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

.result-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-lg);
    margin-bottom: 2rem;
}

.result-card h2 {
    margin-bottom: 1.5rem;
    color: var(--success);
}

.url-display {
    display: flex;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.url-display input {
    flex: 1;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border);
    border-radius: 0.5rem;
    font-size: 1.1rem;
    font-weight: 600;
    background: var(--bg);
    color: var(--primary);
}

.copy-btn, .download-btn, .stats-btn, .new-btn {
    padding: 0.875rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.copy-btn {
    background: var(--success);
    color: white;
}

.copy-btn:hover {
    background: #059669;
}

.copy-btn.copied {
    background: #6366f1;
}

.original-url {
    padding: 1rem;
    background: var(--bg);
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-light);
    word-break: break-all;
}

.qr-code-container {
    text-align: center;
    padding: 1.5rem;
    background: var(--bg);
    border-radius: 0.5rem;
    margin-bottom: 1.5rem;
}

.qr-code-container h3 {
    margin-bottom: 1rem;
}

#qrCode {
    display: inline-block;
    padding: 1rem;
    background: white;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
}

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

.download-btn:hover {
    background: var(--primary-dark);
}

.actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.stats-btn {
    background: #8b5cf6;
    color: white;
    flex: 1;
}

.stats-btn:hover {
    background: #7c3aed;
}

.new-btn {
    background: var(--border);
    color: var(--text);
    flex: 1;
}

.new-btn:hover {
    background: var(--text-light);
    color: white;
}

/* Stats Section */
.stats-section {
    animation: slideIn 0.3s ease-out;
}

.stats-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.stats-header h2 {
    margin: 0;
}

.close-btn {
    background: var(--error);
    color: white;
    border: none;
    border-radius: 50%;
    width: 2.5rem;
    height: 2.5rem;
    font-size: 1.5rem;
    cursor: pointer;
    transition: background 0.2s;
}

.close-btn:hover {
    background: #dc2626;
}

.stats-url-info {
    background: var(--card-bg);
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.stat-card {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
}

.stat-card h3 {
    margin-bottom: 1rem;
    color: var(--primary);
}

.chart-container, .list-container {
    min-height: 200px;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    background: var(--bg);
    border-radius: 0.5rem;
}

.stat-label {
    font-weight: 500;
}

.stat-value {
    font-weight: 700;
    color: var(--primary);
}

.stat-bar {
    height: 0.5rem;
    background: var(--primary);
    border-radius: 0.25rem;
    margin-top: 0.5rem;
    transition: width 0.3s ease-out;
}

.empty-state {
    text-align: center;
    padding: 2rem;
    color: var(--text-light);
}

/* Error Message */
.error-message {
    background: var(--error);
    color: white;
    padding: 1rem 1.5rem;
    border-radius: 0.5rem;
    margin-bottom: 1rem;
    animation: shake 0.3s;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

/* Footer */
.footer {
    text-align: center;
    padding: 2rem 1rem;
    color: var(--text-light);
    margin-top: 3rem;
}

/* Responsive */
@media (max-width: 640px) {
    .header h1 {
        font-size: 2rem;
    }

    .input-group {
        flex-direction: column;
    }

    .url-display {
        flex-direction: column;
    }

    .actions {
        flex-direction: column;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }
}