/* CSS Variables */
:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --download-color: #3b82f6;
    --upload-color: #8b5cf6;
    --ping-color: #06b6d4;
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --bg-card-hover: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --border-color: #334155;
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.3);
    --transition: all 0.3s ease;
}

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

html {
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-dark);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
}

/* App Container */
.app-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    padding: 30px 0;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 10px;
}

.logo-img {
    width: 48px;
    height: 48px;
    border-radius: 12px;
}

header h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-light), var(--primary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.tagline {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Main Content */
main {
    flex: 1;
}

/* Speed Test Section */
.speed-test-section {
    background: var(--bg-card);
    border-radius: 20px;
    padding: 30px;
    margin-bottom: 30px;
    box-shadow: var(--shadow-lg);
}

/* Speed Gauge */
.speed-gauge-container {
    text-align: center;
    margin-bottom: 30px;
}

.speed-gauge {
    position: relative;
    width: 220px;
    height: 140px;
    margin: 0 auto 15px;
}

.gauge-svg {
    width: 100%;
    height: 100%;
}

.gauge-bg {
    fill: none;
    stroke: var(--border-color);
    stroke-width: 12;
    stroke-linecap: round;
}

.gauge-fill {
    fill: none;
    stroke: url(#gaugeGradient);
    stroke-width: 12;
    stroke-linecap: round;
    stroke-dasharray: 251.2;
    stroke-dashoffset: 251.2;
    transition: stroke-dashoffset 0.5s ease;
}

.speed-display {
    position: absolute;
    bottom: 10px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
}

.speed-value {
    font-size: 3rem;
    font-weight: 700;
    display: block;
    line-height: 1;
}

.speed-unit {
    font-size: 1rem;
    color: var(--text-secondary);
}

.test-status {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Start Button */
.start-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    width: 100%;
    max-width: 280px;
    margin: 0 auto 30px;
    padding: 16px 32px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 4px 20px rgba(99, 102, 241, 0.4);
}

.start-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 30px rgba(99, 102, 241, 0.5);
}

.start-btn:active {
    transform: translateY(0);
}

.start-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
    transform: none;
}

.start-btn.testing {
    background: linear-gradient(135deg, var(--warning-color), #d97706);
}

.btn-icon {
    font-size: 1rem;
}

/* Results Grid */
.results-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
}

.result-card {
    background: var(--bg-dark);
    border-radius: 16px;
    padding: 20px 15px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.result-card:hover {
    transform: translateY(-3px);
    border-color: var(--primary-color);
}

.result-icon {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.result-card.download .result-icon { color: var(--download-color); }
.result-card.upload .result-icon { color: var(--upload-color); }
.result-card.ping .result-icon { color: var(--ping-color); }

.result-label {
    display: block;
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 5px;
}

.result-value {
    display: block;
    font-size: 1.6rem;
    font-weight: 700;
}

.result-card.download .result-value { color: var(--download-color); }
.result-card.upload .result-value { color: var(--upload-color); }
.result-card.ping .result-value { color: var(--ping-color); }

.result-unit {
    display: block;
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Share Section */
.share-section {
    margin-top: 25px;
    text-align: center;
}

.share-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--bg-dark);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 30px;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
}

.share-btn:hover {
    background: var(--bg-card-hover);
    border-color: var(--primary-color);
}

/* History Section */
.history-section {
    background: var(--bg-card);
    border-radius: 20px;
    padding: 25px;
    box-shadow: var(--shadow-lg);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.section-header h2 {
    font-size: 1.3rem;
    font-weight: 600;
}

.clear-btn {
    padding: 8px 16px;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
}

.clear-btn:hover {
    background: var(--danger-color);
    color: white;
    border-color: var(--danger-color);
}

.history-list {
    max-height: 400px;
    overflow-y: auto;
}

.empty-history {
    color: var(--text-muted);
    text-align: center;
    padding: 30px;
}

.history-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px;
    background: var(--bg-dark);
    border-radius: 12px;
    margin-bottom: 10px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.history-item:hover {
    border-color: var(--primary-color);
}

.history-date {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.history-stats {
    display: flex;
    gap: 20px;
}

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

.history-stat-label {
    display: block;
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

.history-stat-value {
    font-weight: 600;
    font-size: 0.95rem;
}

.history-stat.download .history-stat-value { color: var(--download-color); }
.history-stat.upload .history-stat-value { color: var(--upload-color); }
.history-stat.ping .history-stat-value { color: var(--ping-color); }

.history-delete {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 5px;
    transition: var(--transition);
}

.history-delete:hover {
    color: var(--danger-color);
}

/* Footer */
footer {
    text-align: center;
    padding: 30px 0 20px;
    margin-top: auto;
}

footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

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

footer a:hover {
    color: var(--primary-color);
    text-decoration: underline;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    border-radius: 20px;
    width: 100%;
    max-width: 450px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.2rem;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition);
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 20px;
}

.share-preview {
    margin-bottom: 20px;
}

.share-card {
    background: linear-gradient(135deg, var(--primary-dark), var(--bg-dark));
    border-radius: 16px;
    padding: 25px;
    text-align: center;
}

.share-card h4 {
    font-size: 1.1rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.share-stats {
    display: flex;
    justify-content: space-around;
    margin-bottom: 15px;
}

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

.stat-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 5px;
}

.stat-value {
    font-size: 1.3rem;
    font-weight: 700;
}

.share-footer {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-top: 15px;
}

.share-options {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
}

.share-option {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    padding: 15px 10px;
    background: var(--bg-dark);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
}

.share-option:hover {
    background: var(--bg-card-hover);
    border-color: var(--primary-color);
}

.share-option span:first-child {
    font-size: 1.3rem;
}

.copy-feedback {
    text-align: center;
    padding: 10px;
    margin-top: 15px;
    background: var(--success-color);
    border-radius: 8px;
    font-size: 0.9rem;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.copy-feedback.show {
    opacity: 1;
}

/* Scrollbar */
.history-list::-webkit-scrollbar {
    width: 6px;
}

.history-list::-webkit-scrollbar-track {
    background: var(--bg-dark);
    border-radius: 3px;
}

.history-list::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.history-list::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* Responsive Design */
@media (max-width: 600px) {
    .app-container {
        padding: 15px;
    }

    header {
        padding: 20px 0;
    }

    .logo {
        flex-direction: column;
        gap: 8px;
    }

    header h1 {
        font-size: 1.5rem;
    }

    .speed-test-section {
        padding: 20px;
    }

    .speed-gauge {
        width: 180px;
        height: 115px;
    }

    .speed-value {
        font-size: 2.5rem;
    }

    .results-grid {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .result-card {
        display: flex;
        align-items: center;
        gap: 15px;
        padding: 15px 20px;
        text-align: left;
    }

    .result-icon {
        margin-bottom: 0;
        font-size: 1.8rem;
    }

    .result-info {
        flex: 1;
        display: flex;
        align-items: baseline;
        gap: 8px;
    }

    .result-label {
        margin-bottom: 0;
    }

    .result-value {
        font-size: 1.4rem;
    }

    .history-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .history-info {
        width: 100%;
    }

    .history-stats {
        width: 100%;
        justify-content: space-between;
    }

    .history-delete {
        position: absolute;
        right: 15px;
        top: 15px;
    }

    .history-item {
        position: relative;
    }

    .share-options {
        grid-template-columns: 1fr;
    }

    .share-option {
        flex-direction: row;
        justify-content: center;
    }
}

/* Animation */
@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.05); }
}

.testing .speed-display {
    animation: pulse 1s infinite;
}

/* Gradient for gauge */
.gauge-svg defs {
    display: block;
}