/* ============================================
   NetCheck — Dark Theme, Glassmorphism
   ============================================ */

:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-card: rgba(17, 24, 39, 0.7);
    --bg-glass: rgba(255, 255, 255, 0.03);
    --border-glass: rgba(255, 255, 255, 0.08);
    --text-primary: #f0f4f8;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent: #06d6a0;
    --accent-secondary: #118ab2;
    --accent-upload: #8b5cf6;
    --accent-ping: #f59e0b;
    --accent-gradient: linear-gradient(135deg, #06d6a0, #118ab2);
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    overflow-x: hidden;
    background-image:
        radial-gradient(ellipse at 20% 50%, rgba(6, 214, 160, 0.05) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(17, 138, 178, 0.05) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 80%, rgba(139, 92, 246, 0.03) 0%, transparent 50%);
}

/* --- Header --- */
.header {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 32px;
    background: rgba(10, 14, 26, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-glass);
}

.header__logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.header__icon {
    display: flex;
    align-items: center;
    justify-content: center;
}

.header__title {
    font-size: 1.25rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.header__nav {
    display: flex;
    gap: 24px;
}

.header__link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 500;
    transition: color var(--transition);
    position: relative;
}

.header__link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    transition: width var(--transition);
    border-radius: 1px;
}

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

.header__link:hover::after {
    width: 100%;
}

/* --- Main --- */
.main {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 24px 60px;
}

/* --- Section --- */
.section {
    margin-bottom: 64px;
}

.section__title {
    font-size: 1.75rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 6px;
}

.section__subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 32px;
}

/* --- IP Card --- */
.ip-card {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius);
    padding: 32px;
    margin-bottom: 24px;
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
}

.ip-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(6, 214, 160, 0.05), transparent 60%);
    pointer-events: none;
}

.ip-card__address {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    font-variant-numeric: tabular-nums;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.ip-card__loading {
    font-size: 1.5rem;
    font-weight: 400;
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

.ip-card__copy {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 0.8rem;
    font-family: inherit;
    transition: all var(--transition);
}

.ip-card__copy:hover {
    background: rgba(255, 255, 255, 0.08);
    color: var(--text-primary);
    border-color: var(--accent);
}

.ip-card__copy.copied {
    color: var(--accent);
    border-color: var(--accent);
}

/* --- Info Grid --- */
.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
    gap: 12px;
}

.info-card {
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-sm);
    padding: 20px;
    backdrop-filter: blur(10px);
    transition: border-color var(--transition), transform var(--transition);
}

.info-card:hover {
    border-color: rgba(6, 214, 160, 0.2);
    transform: translateY(-2px);
}

.info-card__icon {
    font-size: 1.25rem;
    margin-bottom: 8px;
}

.info-card__label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
    margin-bottom: 4px;
}

.info-card__value {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    word-break: break-all;
}

/* --- Speed Gauges --- */
.speed-gauges {
    display: flex;
    justify-content: center;
    gap: 32px;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

.gauge {
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: 180px;
}

.gauge--small {
    width: 150px;
}

.gauge__svg {
    width: 160px;
    height: 160px;
    transform: rotate(-90deg);
}

.gauge--small .gauge__svg {
    width: 130px;
    height: 130px;
}

.gauge__bg {
    fill: none;
    stroke: var(--border-glass);
    stroke-width: 8;
}

.gauge__fill {
    fill: none;
    stroke: url(#gauge-gradient-download);
    stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 440;
    stroke-dashoffset: 440;
    transition: stroke-dashoffset 1s ease-out;
    filter: drop-shadow(0 0 8px rgba(6, 214, 160, 0.4));
}

.gauge__fill--upload {
    stroke: var(--accent-upload);
    filter: drop-shadow(0 0 8px rgba(139, 92, 246, 0.4));
}

.gauge__fill--ping {
    stroke: var(--accent-ping);
    filter: drop-shadow(0 0 8px rgba(245, 158, 11, 0.4));
}

.gauge__content {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -60%);
    text-align: center;
}

.gauge__value {
    font-size: 2rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.02em;
}

.gauge__unit {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.gauge__label {
    margin-top: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.02em;
}

/* --- Start Button --- */
.btn-start {
    display: block;
    margin: 0 auto 20px;
    padding: 16px 56px;
    background: var(--accent-gradient);
    border: none;
    border-radius: 50px;
    color: #0a0e1a;
    font-family: inherit;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
    box-shadow: 0 4px 24px rgba(6, 214, 160, 0.25);
    letter-spacing: 0.02em;
}

.btn-start:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 32px rgba(6, 214, 160, 0.35);
}

.btn-start:active:not(:disabled) {
    transform: translateY(0);
}

.btn-start:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.btn-start__progress {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.15);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s linear;
    pointer-events: none;
}

/* --- Speed Status --- */
.speed-status {
    text-align: center;
    font-size: 0.85rem;
    color: var(--text-muted);
    min-height: 24px;
    transition: color var(--transition);
}

.speed-status--active {
    color: var(--accent);
}

.speed-status--error {
    color: #ef4444;
}

/* --- Footer --- */
.footer {
    text-align: center;
    padding: 32px 24px;
    border-top: 1px solid var(--border-glass);
    color: var(--text-muted);
    font-size: 0.8rem;
}

/* --- Responsive --- */
@media (max-width: 600px) {
    .header {
        padding: 14px 16px;
    }

    .header__nav {
        gap: 16px;
    }

    .main {
        padding: 24px 16px 40px;
    }

    .section__title {
        font-size: 1.375rem;
    }

    .ip-card {
        flex-direction: column;
        padding: 24px 20px;
    }

    .ip-card__address {
        font-size: 1.75rem;
    }

    .speed-gauges {
        gap: 20px;
    }

    .gauge {
        width: 140px;
    }

    .gauge__svg {
        width: 130px;
        height: 130px;
    }

    .gauge__value {
        font-size: 1.5rem;
    }

    .gauge--small {
        width: 120px;
    }

    .gauge--small .gauge__svg {
        width: 110px;
        height: 110px;
    }
}

/* --- Animations --- */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section {
    animation: fadeInUp 0.6s ease-out backwards;
}

#speed-section {
    animation-delay: 0.15s;
}