@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --bg-color: #f8fafc; /* Slate 50 */
    --card-bg: #ffffff;
    --text-main: #0f172a; /* Slate 900 */
    --text-secondary: #475569; /* Slate 600 */
    --text-muted: #94a3b8; /* Slate 400 */
    --primary: #2563eb; /* Royal Blue */
    --primary-hover: #1d4ed8;
    --primary-light: #eff6ff;
    --border-color: #e2e8f0; /* Slate 200 */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-premium: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-full: 9999px;
}

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

html, body {
    height: 100%;
    margin: 0;
    padding: 0;
    background-color: var(--bg-color);
    color: var(--text-main);
    font-family: var(--font-sans);
    -webkit-font-smoothing: antialiased;
}

body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* Main Wrapper */
.iss-main-wrapper {
    flex: 1 0 auto;
    width: 100%;
    max-width: 1300px;
    margin: 0 auto;
    padding: 100px 20px 40px; /* Header yüksekliğine göre üstten boşluk bırakıldı */
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

/* Header (Navigasyon Menüsü) */
.iss-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 70px;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    display: flex;
    align-items: center;
    transition: var(--transition);
}

.iss-header-container {
    width: 100%;
    max-width: 1300px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.iss-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-main);
    font-weight: 700;
    font-size: 1.2rem;
    letter-spacing: -0.02em;
    transition: var(--transition);
}

.iss-brand:hover {
    opacity: 0.9;
    transform: translateY(-1px);
}

.iss-brand-icon {
    font-size: 1.4rem;
}

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

.iss-nav-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 600;
    transition: var(--transition);
    padding: 8px 16px;
    border-radius: var(--radius-md);
}

.iss-nav-link:hover {
    color: var(--primary);
    background: var(--primary-light);
}

.iss-nav-link.active {
    color: var(--primary);
    background: var(--primary-light);
}

/* Mobil Hamburger Menü */
.iss-nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
}

.iss-nav-toggle-icon {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--text-main);
    position: relative;
    transition: var(--transition);
}

.iss-nav-toggle-icon::before,
.iss-nav-toggle-icon::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 2px;
    background: var(--text-main);
    left: 0;
    transition: var(--transition);
}

.iss-nav-toggle-icon::before {
    top: -6px;
}

.iss-nav-toggle-icon::after {
    bottom: -6px;
}

/* Hamburger Açık Hali */
.iss-header.menu-open .iss-nav-toggle-icon {
    background: transparent;
}

.iss-header.menu-open .iss-nav-toggle-icon::before {
    transform: rotate(45deg);
    top: 0;
}

.iss-header.menu-open .iss-nav-toggle-icon::after {
    transform: rotate(-45deg);
    bottom: 0;
}

@media (max-width: 768px) {
    .iss-nav-toggle {
        display: block;
    }
    .iss-nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--card-bg);
        border-bottom: 1px solid var(--border-color);
        flex-direction: column;
        gap: 8px;
        padding: 20px;
        transform: translateY(-120%);
        opacity: 0;
        pointer-events: none;
        transition: var(--transition);
        box-shadow: var(--shadow-lg);
    }
    .iss-header.menu-open .iss-nav {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }
    .iss-nav-link {
        width: 100%;
        text-align: center;
        padding: 12px;
    }
}

/* Premium Kart & Konteyner */
.iss-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-premium);
    padding: 35px;
    transition: var(--transition);
    text-align: center;
}

.iss-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.iss-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-main);
    letter-spacing: -0.02em;
    margin: 10px 0;
}

.iss-subtitle {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 25px;
}

/* Footer (Ortak Alt Bilgi Alanı) */
.iss-footer {
    flex-shrink: 0;
    background: var(--card-bg);
    border-top: 1px solid var(--border-color);
    padding: 30px 20px;
    text-align: center;
    margin-top: auto;
}

.iss-footer-container {
    max-width: 1300px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.iss-footer-links {
    display: flex;
    gap: 20px;
    margin-bottom: 5px;
    flex-wrap: wrap;
    justify-content: center;
}

.iss-footer-link {
    text-decoration: none;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-weight: 600;
    transition: var(--transition);
}

.iss-footer-link:hover {
    color: var(--primary);
}

.iss-footer-motto {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-style: italic;
    max-width: 500px;
    line-height: 1.5;
}

.iss-footer-copyright {
    font-size: 0.7rem;
    color: var(--text-muted);
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

/* Aktif Test Kartı Efektleri */
.result-box {
    transition: var(--transition);
}

.result-box.active {
    border-color: var(--primary);
    box-shadow: 0 0 15px rgba(37, 99, 235, 0.12);
    background: var(--primary-light);
    transform: translateY(-2px);
}

/* Durdur/İptal Et Butonu */
.btn-start-test.running {
    background: #ef4444 !important;
    box-shadow: 0 4px 14px rgba(239, 68, 68, 0.25) !important;
}

.btn-start-test.running:hover {
    background: #dc2626 !important;
    box-shadow: 0 6px 20px rgba(239, 68, 68, 0.35) !important;
}

/* Hız & Gecikme Grafiği Kartı */
.chart-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 25px;
    margin-top: 30px;
    text-align: left;
    box-shadow: var(--shadow-premium);
    display: none;
    animation: fadeIn 0.4s ease;
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    flex-wrap: wrap;
    gap: 10px;
}

.chart-title {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-main);
}

.chart-legend {
    display: flex;
    gap: 15px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.legend-color {
    width: 12px;
    height: 12px;
    border-radius: 3px;
}

.legend-speed { background-color: #2563eb; }
.legend-ping { background-color: #f59e0b; }

.chart-container {
    position: relative;
    width: 100%;
    height: 220px;
}

#realtimeChart {
    width: 100%;
    height: 100%;
    display: block;
}

/* Sıkça Sorulan Sorular (Bilgi Paneli) */
.info-section {
    margin-top: 50px;
    text-align: left;
    border-top: 1px solid var(--border-color);
    padding-top: 40px;
    width: 100%;
}

.info-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 25px;
    text-align: center;
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.faq-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.faq-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--border-color);
}

.faq-question {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.faq-answer {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

@media (max-width: 768px) {
    .faq-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }
}

/* Yetenekler Listesi (Grade Kartı İçi) */
.capabilities-container {
    margin-top: 25px;
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
    text-align: left;
}

.capabilities-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 15px;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.cap-item {
    display: flex;
    align-items: center;
    background: var(--bg-color);
    padding: 10px 14px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    gap: 10px;
}

.cap-icon {
    font-size: 1.25rem;
}

.cap-details {
    display: flex;
    flex-direction: column;
    gap: 2px;
    width: 100%;
}

.cap-name {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-main);
}

.cap-status {
    font-size: 0.72rem;
    font-weight: 700;
    display: inline-block;
    padding: 1px 6px;
    border-radius: 4px;
    width: fit-content;
}

.status-good { background: #dcfce7; color: #166534; }
.status-warn { background: #fef3c7; color: #92400e; }
.status-bad { background: #fee2e2; color: #991b1b; }

/* Geçmiş Testler Kartı */
.history-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 25px;
    margin-top: 30px;
    box-shadow: var(--shadow-premium);
    text-align: left;
    display: none;
    animation: fadeIn 0.4s ease;
}

.history-title {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 15px;
    text-align: center;
}

.history-table-wrapper {
    overflow-x: auto;
    width: 100%;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.history-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.8rem;
    text-align: left;
    white-space: nowrap;
}

.history-table th {
    background: var(--bg-color);
    color: var(--text-secondary);
    font-weight: 700;
    padding: 10px 12px;
    border-bottom: 2px solid var(--border-color);
}

.history-table td {
    padding: 10px 12px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
    vertical-align: middle;
}

.history-table tr:last-child td {
    border-bottom: none;
}

.history-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    color: white;
    font-size: 0.75rem;
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.btn-clear-history {
    background: transparent;
    color: #ef4444;
    border: 1px solid #fee2e2;
    padding: 6px 12px;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    margin-top: 15px;
    display: block;
    margin-left: auto;
    transition: var(--transition);
}

.btn-clear-history:hover {
    background: #fee2e2;
}

@media (max-width: 600px) {
    .capabilities-grid {
        grid-template-columns: 1fr;
    }
}