:root {
    --color-ink: #14232B;
    --color-ink-2: #1B2F38;
    --color-teal: #0E6E6B;
    --color-teal-dark: #0A524F;
    --color-teal-light: #E3F1F0;
    --color-brass: #A97D3D;
    --color-brass-light: #F7EEDD;
    --color-paper: #F7F6F2;
    --color-surface: #FFFFFF;
    --color-border: #E3E0D8;
    --color-text: #1B2528;
    --color-text-muted: #5F6D70;
    --color-success: #2F7D52;
    --color-success-bg: #E7F3EC;
    --color-warning: #A97D3D;
    --color-warning-bg: #F7EEDD;
    --color-error: #B33A3A;
    --color-error-bg: #FBEAEA;
    --color-info: #2C5F8A;
    --color-info-bg: #E8EFF5;
    --color-purple: #6E5A96;
    --color-purple-bg: #ECE8F3;
    --radius: 8px;
    --shadow: 0 1px 3px rgba(20,35,43,0.08), 0 1px 2px rgba(20,35,43,0.05);
    --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'IBM Plex Mono', ui-monospace, "SF Mono", Consolas, monospace;
}

* { box-sizing: border-box; }
.skip-link {
    position: absolute; left: -9999px; top: 0; z-index: 1000;
    background: var(--color-teal); color: #fff; padding: 10px 16px; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }
body {
    margin: 0;
    font-family: var(--font-sans);
    background: var(--color-paper);
    color: var(--color-text);
    font-size: 14px;
    line-height: 1.5;
}
h1, h2, h3 { margin: 0 0 12px; font-weight: 600; }
a { color: var(--color-teal); text-decoration: none; }
a:hover { text-decoration: underline; }
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; letter-spacing: -0.01em; }

/* ---- Giriş / Kurulum Sayfaları ---- */
.login-body {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(165deg, #0F1B21 0%, var(--color-ink-2) 100%);
}
.login-box {
    background: var(--color-surface);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.35);
    width: 100%;
    max-width: 400px;
}
.login-logo { text-align: center; margin-bottom: 24px; color: var(--color-teal); }
.login-logo h1 { font-size: 17px; color: var(--color-ink); margin-top: 10px; line-height: 1.3; }
.login-footer { text-align: center; margin-top: 16px; font-size: 13px; color: var(--color-text-muted); }

/* ---- Uygulama Yerleşimi ---- */
.app-layout { display: flex; min-height: 100vh; }
.sidebar {
    width: 240px;
    flex-shrink: 0;
    background: var(--color-ink);
    color: #B9C7CB;
    display: flex;
    flex-direction: column;
    padding: 20px 0;
    height: 100vh;
    position: sticky;
    top: 0;
    overflow-y: auto;
    scrollbar-width: thin;
}
.sidebar::-webkit-scrollbar { width: 6px; }
.sidebar::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.15); border-radius: 3px; }
.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 0 20px 20px;
    font-weight: 600;
    color: #fff;
    border-bottom: 1px solid rgba(255,255,255,0.08);
    margin-bottom: 12px;
}
.brand-mark { color: #3FB6B0; flex-shrink: 0; }
.brand-text { font-size: 13px; line-height: 1.35; }
.sidebar-nav { display: flex; flex-direction: column; gap: 1px; padding: 0 10px; }
.sidebar-nav > a {
    display: flex; align-items: center; gap: 10px;
    color: #B9C7CB;
    padding: 9px 12px;
    border-radius: var(--radius);
    font-size: 13.5px;
    border-left: 3px solid transparent;
    transition: background 0.15s ease, color 0.15s ease;
}
.sidebar-nav > a:hover { background: rgba(255,255,255,0.06); text-decoration: none; color: #fff; }
.sidebar-nav > a.active { background: rgba(63,182,176,0.14); color: #fff; border-left-color: #3FB6B0; font-weight: 500; }

.nav-section { margin-top: 2px; }
.nav-section-header {
    width: 100%; display: flex; justify-content: space-between; align-items: center;
    background: none; border: none; cursor: pointer;
    color: #7C8A96; font-family: inherit;
    font-size: 10.5px; font-weight: 600; letter-spacing: 0.07em; text-transform: uppercase;
    padding: 14px 12px 6px;
}
.nav-section-header:hover { color: #B9C7CB; }
.nav-section-header .chevron { transition: transform 0.2s ease; flex-shrink: 0; }
.nav-section.collapsed .nav-section-header .chevron { transform: rotate(-90deg); }
.nav-section-items { display: flex; flex-direction: column; gap: 1px; overflow: hidden; }
.nav-section.collapsed .nav-section-items { display: none; }
.nav-section-items a {
    display: flex; align-items: center; gap: 10px;
    color: #B9C7CB;
    padding: 8px 12px;
    border-radius: var(--radius);
    font-size: 13px;
    border-left: 3px solid transparent;
    transition: background 0.15s ease, color 0.15s ease;
}
.nav-section-items a:hover { background: rgba(255,255,255,0.06); text-decoration: none; color: #fff; }
.nav-section-items a.active { background: rgba(63,182,176,0.14); color: #fff; border-left-color: #3FB6B0; font-weight: 500; }
.sidebar-lang { display: flex; gap: 6px; padding: 14px 20px 0; margin-top: 10px; border-top: 1px solid rgba(255,255,255,0.08); }
.lang-link { color: #8290a0; font-size: 12px; font-weight: 600; padding: 4px 8px; border-radius: 6px; }
.lang-link:hover { background: rgba(255,255,255,0.08); text-decoration: none; }
.lang-link.active { background: var(--color-teal-dark); color: #fff; }

.main-content { flex: 1; display: flex; flex-direction: column; min-width: 0; }
.topbar {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 14px 24px;
    display: flex;
    align-items: center;
    gap: 16px;
}
.topbar-title { font-weight: 600; font-size: 16px; flex: 1; }
.topbar-user { display: flex; align-items: center; gap: 10px; font-size: 13px; color: var(--color-text-muted); }
.role-tag {
    background: var(--color-teal-light);
    color: var(--color-teal-dark);
    padding: 2px 9px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}
.btn-logout {
    display: inline-flex; align-items: center; gap: 6px;
    background: var(--color-error-bg);
    color: var(--color-error);
    padding: 6px 12px;
    border-radius: var(--radius);
    font-size: 13px;
}
.btn-logout:hover { text-decoration: none; opacity: 0.85; }
.sidebar-toggle {
    display: none;
    background: none; border: none; color: var(--color-text); cursor: pointer; padding: 4px;
}
.page-content { padding: 24px; flex: 1; }

/* ---- Bildirimler ---- */
.alert { padding: 12px 16px; border-radius: var(--radius); margin-bottom: 16px; font-size: 13px; }
.alert ul { margin: 0; padding-left: 18px; }
.alert-success { background: var(--color-success-bg); color: var(--color-success); }
.alert-error { background: var(--color-error-bg); color: var(--color-error); }
.alert-warning { background: var(--color-warning-bg); color: var(--color-warning); }

/* ---- İstatistik Kartları (Kontrol Paneli) ---- */
.stat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; margin-bottom: 24px; }
.stat-card {
    background: var(--color-surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 18px;
    display: flex;
    align-items: center;
    gap: 14px;
}
.stat-icon { width: 42px; height: 42px; border-radius: 10px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.stat-icon.blue { background: var(--color-info-bg); color: var(--color-info); }
.stat-icon.teal { background: var(--color-teal-light); color: var(--color-teal-dark); }
.stat-icon.orange { background: var(--color-warning-bg); color: var(--color-warning); }
.stat-icon.green { background: var(--color-success-bg); color: var(--color-success); }
.stat-value { font-size: 22px; font-weight: 600; font-family: var(--font-mono); }
.stat-label { font-size: 12px; color: var(--color-text-muted); }

.panel-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* ---- Paneller / Kartlar ---- */
.panel {
    background: var(--color-surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px;
    margin-bottom: 16px;
}
.panel h2 { font-size: 15px; display: flex; align-items: center; gap: 8px; }
.form-panel { max-width: 920px; }
.form-section-title {
    font-size: 12.5px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 8px;
    margin: 24px 0 16px;
    font-weight: 600;
}
.form-section-title:first-child { margin-top: 0; }

/* ---- Sayfa Başlığı / Filtreler ---- */
.page-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; gap: 12px; flex-wrap: wrap; }
.search-form { display: flex; gap: 8px; }
.search-form input { padding: 8px 12px; border: 1px solid var(--color-border); border-radius: var(--radius); min-width: 220px; font-family: inherit; }
.filter-tabs { display: flex; gap: 4px; flex-wrap: wrap; }
.filter-tab {
    padding: 7px 14px;
    border-radius: 20px;
    font-size: 13px;
    color: var(--color-text-muted);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
}
.filter-tab:hover { text-decoration: none; border-color: var(--color-teal); }
.filter-tab.active { background: var(--color-teal); color: #fff; border-color: var(--color-teal); }

/* ---- Tablolar ---- */
.table-scroll { overflow-x: auto; }
.data-table { width: 100%; border-collapse: collapse; font-size: 13px; }
.data-table th {
    text-align: left;
    padding: 10px 12px;
    background: var(--color-paper);
    color: var(--color-text-muted);
    font-weight: 600;
    border-bottom: 1px solid var(--color-border);
    white-space: nowrap;
}
.data-table td { padding: 10px 12px; border-bottom: 1px solid var(--color-border); vertical-align: middle; }
.data-table tbody tr:hover { background: #fafaf8; }
.data-table input, .data-table select { width: 100%; padding: 6px 8px; border: 1px solid var(--color-border); border-radius: 6px; font-size: 13px; font-family: inherit; }
.empty-state { text-align: center; color: var(--color-text-muted); padding: 24px !important; }
.actions { display: flex; gap: 4px; white-space: nowrap; }
.inline-form { display: inline; }

/* ---- Rozetler ---- */
.badge { display: inline-block; padding: 3px 10px; border-radius: 20px; font-size: 12px; font-weight: 600; }
.badge-blue { background: var(--color-info-bg); color: var(--color-info); }
.badge-green { background: var(--color-success-bg); color: var(--color-success); }
.badge-orange { background: var(--color-warning-bg); color: var(--color-warning); }
.badge-red { background: var(--color-error-bg); color: var(--color-error); }
.badge-purple { background: var(--color-purple-bg); color: var(--color-purple); }
.badge-gray { background: #eef0ee; color: var(--color-text-muted); }

/* ---- Butonlar ---- */
.btn {
    display: inline-flex; align-items: center; gap: 7px;
    padding: 9px 16px;
    border-radius: var(--radius);
    font-size: 13px;
    font-weight: 600;
    border: 1px solid transparent;
    cursor: pointer;
    font-family: inherit;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--color-teal); color: #fff; }
.btn-primary:hover { background: var(--color-teal-dark); }
.btn-secondary { background: var(--color-surface); color: var(--color-text); border-color: var(--color-border); }
.btn-secondary:hover { background: var(--color-paper); }
.btn-block { width: 100%; justify-content: center; }
.btn-sm { padding: 6px 12px; font-size: 12px; }
.btn-icon {
    background: none; border: none; cursor: pointer;
    color: var(--color-text-muted);
    padding: 5px; border-radius: 6px;
    display: inline-flex; align-items: center;
}
.btn-icon:hover { background: var(--color-paper); color: var(--color-text); }

/* ---- Formlar ---- */
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-group { margin-bottom: 14px; }
.form-group label { display: block; margin-bottom: 6px; font-size: 13px; font-weight: 600; color: var(--color-text); }
.form-checkbox label { display: flex; align-items: center; gap: 8px; font-weight: 400; margin-top: 26px; }
.form-group input[type=text], .form-group input[type=email], .form-group input[type=password],
.form-group input[type=date], .form-group select, .form-group textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: 14px;
    font-family: inherit;
    background: #fff;
    color: var(--color-text);
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    outline: none; border-color: var(--color-teal); box-shadow: 0 0 0 3px var(--color-teal-light);
}
.form-group textarea { resize: vertical; }
.form-actions { display: flex; gap: 10px; margin-top: 20px; padding-top: 16px; border-top: 1px solid var(--color-border); }

/* ---- Sertifika Yazdırma Görünümü ---- */
.certificate-sheet {
    background: var(--color-surface);
    max-width: 850px;
    margin: 0 auto;
    padding: 40px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.certificate-header { display: flex; align-items: center; gap: 16px; border-bottom: 3px solid var(--color-teal); padding-bottom: 16px; margin-bottom: 20px; }
.certificate-header .brand-mark { color: var(--color-teal); }
.certificate-header h1 { font-size: 19px; margin: 0; letter-spacing: 0.02em; }
.certificate-header p { margin: 2px 0 0; color: var(--color-text-muted); font-size: 12px; }
.certificate-sheet h3 { font-size: 13px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-text-muted); margin-top: 22px; }
.certificate-meta { width: 100%; border-collapse: collapse; margin-bottom: 10px; font-size: 13px; }
.certificate-meta td { padding: 5px 4px; }
.certificate-signature { display: flex; justify-content: space-between; margin-top: 60px; text-align: center; font-size: 13px; gap: 40px; }
.certificate-signature > div { flex: 1; }
.certificate-footer-note { margin-top: 30px; font-size: 11px; color: var(--color-text-muted); font-style: italic; border-top: 1px solid var(--color-border); padding-top: 12px; }

/* ---- Karanlık Mod ---- */
[data-theme="dark"] {
    --color-ink: #0D1418;
    --color-ink-2: #131C22;
    --color-teal-light: #163430;
    --color-brass-light: #3A2E1A;
    --color-paper: #171D22;
    --color-surface: #1F262C;
    --color-border: #323B42;
    --color-text: #E7EBEE;
    --color-text-muted: #8D9AA3;
    --color-success-bg: #17321F;
    --color-warning-bg: #362A14;
    --color-error-bg: #3A1E1E;
    --color-info-bg: #17293B;
    --color-purple-bg: #26203A;
}
[data-theme="dark"] body { background: var(--color-paper); color: var(--color-text); }
[data-theme="dark"] .form-group input[type=text],
[data-theme="dark"] .form-group input[type=email],
[data-theme="dark"] .form-group input[type=password],
[data-theme="dark"] .form-group input[type=date],
[data-theme="dark"] .form-group select,
[data-theme="dark"] .form-group textarea,
[data-theme="dark"] .data-table input,
[data-theme="dark"] .data-table select { background: var(--color-ink-2); color: var(--color-text); }
[data-theme="dark"] .certificate-sheet { background: var(--color-surface); }
[data-theme="dark"] .login-body { background: linear-gradient(165deg, #05080a 0%, #10161a 100%); }

.theme-toggle {
    background: none; border: none; cursor: pointer; color: inherit;
    display: inline-flex; align-items: center; padding: 4px;
}

/* ---- Yazdırma ---- */
@media print {
    .sidebar, .topbar, .no-print { display: none !important; }
    .app-layout { display: block; }
    .page-content { padding: 0; }
    .certificate-sheet { box-shadow: none; padding: 0; max-width: 100%; }
    body { background: #fff; }
}

/* ---- Duyarlı (Responsive) Tasarım ---- */
@media (max-width: 900px) {
    .stat-grid { grid-template-columns: repeat(2, 1fr); }
    .panel-grid { grid-template-columns: 1fr; }
    .form-row { grid-template-columns: 1fr; }
}
@media (max-width: 700px) {
    .sidebar-toggle { display: block; }
    .sidebar {
        position: fixed; left: -240px; top: 0; bottom: 0; z-index: 100;
        transition: left 0.2s ease;
    }
    .sidebar.open { left: 0; }
    .stat-grid { grid-template-columns: 1fr; }
    .topbar-user span:first-child { display: none; }
    .certificate-sheet { padding: 20px; }
}