/* --- TEMEL ARAYÜZ SIFIRLAMALARI --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, Roboto, sans-serif;
}

body {
    display: flex;
    min-height: 100vh;
    background-color: #f1f5f9;
    color: #334155;
}

.app-container {
    display: flex;
    width: 100%;
    min-height: 100vh;
}

/* --- SOL DİKEY MENÜ (SIDEBAR) --- */
.sidebar {
    width: 280px;
    height: 100vh;
    position: fixed;
    top: 0;
    left: 0;
    background: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
    color: #ffffff;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 2.5rem 1.5rem 1.5rem;
    box-sizing: border-box;
    z-index: 1000;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.08);
}

.logo {
    text-align: center;
}

.logo-img {
    width: 150px;
    height: 150px;
    border-radius: 20px;
    object-fit: cover;
    margin: 0 auto 1.25rem;
    border: 3px solid rgba(255, 255, 255, 0.15);
    display: block;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
}

.logo-img:hover {
    transform: scale(1.03);
}

.logo h2 {
    font-size: 1.2rem;
    color: #f8fafc;
    font-weight: 700;
    line-height: 1.3;
}

.logo span {
    font-size: 0.78rem;
    color: #38bdf8;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
    display: inline-block;
    margin-top: 0.4rem;
}

.nav-menu {
    margin-top: 2rem;
    flex-grow: 1;
}

.nav-menu ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.nav-menu a {
    color: #94a3b8;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 0.85rem 1.2rem;
    border-radius: 12px;
    font-size: 0.95rem;
    font-weight: 500;
    transition: all 0.25s ease;
}

.nav-menu a:hover,
.nav-menu a.active {
    background: rgba(56, 189, 248, 0.12);
    color: #38bdf8;
    font-weight: 600;
}

.nav-menu a i {
    font-size: 1.1rem;
    width: 20px;
    text-align: center;
}

.sidebar-footer {
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    text-align: center;
}

.whatsapp-btn {
    width: 100%;
    background-color: #25d366;
    color: #ffffff;
    border: none;
    padding: 0.85rem 1rem;
    border-radius: 12px;
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    box-shadow: 0 4px 12px rgba(37, 211, 102, 0.25);
    transition: all 0.25s ease;
}

.whatsapp-btn:hover {
    background-color: #22c55e;
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(37, 211, 102, 0.35);
}

/* --- SAĞ ANA İÇERİK ALANI --- */
.main-content {
    margin-left: 280px;
    flex: 1;
    padding: 3rem;
    min-height: 100vh;
    box-sizing: border-box;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.content-header {
    width: 100%;
    max-width: 900px;
    margin-bottom: 2.5rem;
    text-align: center;
}

.content-header h1 {
    color: #0f172a;
    font-size: 2.2rem;
    font-weight: 800;
    margin-bottom: 0.6rem;
    letter-spacing: -0.5px;
}

.content-header p {
    color: #64748b;
    font-size: 1.05rem;
    line-height: 1.6;
}

/* --- HER BÖLÜM İÇİN DÜZENLİ GENİŞLİK VE ORTALAMA --- */
.hero-card,
.tax-calendar-bar,
.features-grid,
.about-section,
.services-section,
.calc-section {
    width: 100%;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

/* --- HERO KARŞILAMA KARTI --- */
.hero-card {
    background: #ffffff;
    padding: 3rem;
    border-radius: 20px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.03);
    margin-bottom: 2rem;
    text-align: center;
}

.hero-card .badge {
    background-color: #e0f2fe;
    color: #0284c7;
    font-size: 0.85rem;
    font-weight: 600;
    padding: 6px 16px;
    border-radius: 30px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 1.5rem;
}

.hero-card h1 {
    font-size: 2.2rem;
    color: #0f172a;
    line-height: 1.3;
    margin-bottom: 1rem;
}

.hero-card p {
    font-size: 1.05rem;
    color: #475569;
    max-width: 700px;
    margin: 0 auto 2rem;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.btn {
    padding: 0.85rem 1.8rem;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: all 0.25s ease;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary {
    background-color: #0f172a;
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(15, 23, 42, 0.2);
}

.btn-primary:hover {
    background-color: #1e293b;
}

.btn-whatsapp {
    background-color: #25d366;
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(37, 211, 102, 0.2);
}

/* --- MALİ TAKVİM BANDI --- */
.tax-calendar-bar {
    background: linear-gradient(135deg, #0284c7 0%, #0369a1 100%);
    color: #ffffff;
    padding: 1.5rem 2rem;
    border-radius: 16px;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: 0 10px 25px rgba(2, 132, 199, 0.2);
}

.calendar-icon {
    font-size: 1.8rem;
    background: rgba(255, 255, 255, 0.15);
    width: 56px;
    height: 56px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.calendar-info h4 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.calendar-info p {
    font-size: 0.95rem;
    opacity: 0.95;
    line-height: 1.5;
}

/* --- KART DİZİLİMLERİ (GRID) --- */
.features-grid,
.about-grid,
.services-grid,
.calc-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.feature-card,
.about-card,
.about-details,
.service-card,
.calc-card {
    background-color: #ffffff;
    padding: 2rem;
    border-radius: 16px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.03);
    transition: all 0.3s ease;
}

.feature-card:hover,
.service-card:hover,
.calc-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.06);
    border-color: #cbd5e1;
}

.feature-card i,
.about-card i,
.service-card i {
    font-size: 2rem;
    color: #0284c7;
    margin-bottom: 1.25rem;
}

.feature-card h3,
.about-card h3,
.service-card h3,
.calc-card h3 {
    font-size: 1.2rem;
    color: #0f172a;
    font-weight: 700;
    margin-bottom: 0.75rem;
}

.calc-card h3 {
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.feature-card p,
.about-card p,
.about-details p,
.service-card p {
    font-size: 0.95rem;
    color: #64748b;
    line-height: 1.6;
}

/* --- PRATİK HESAPLAMALAR SAYFASI TASARIMI --- */
.calc-card {
    display: flex;
    flex-direction: column;
}

.form-group {
    margin-bottom: 1.25rem;
    text-align: left;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: #475569;
    margin-bottom: 0.5rem;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.8rem 1rem;
    background-color: #f8fafc;
    border: 1px solid #cbd5e1;
    border-radius: 10px;
    font-size: 0.95rem;
    color: #0f172a;
    outline: none;
    transition: all 0.2s ease;
    box-sizing: border-box;
}

.form-group input:focus,
.form-group select:focus {
    background-color: #ffffff;
    border-color: #0284c7;
    box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.12);
}

.calc-buttons {
    display: flex;
    gap: 0.75rem;
    margin-top: 1rem;
}

.calc-buttons button,
.full-btn {
    flex: 1;
    background-color: #0f172a;
    color: #ffffff;
    border: none;
    padding: 0.85rem 1rem;
    border-radius: 10px;
    font-weight: 600;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.calc-buttons button:hover,
.full-btn:hover {
    background-color: #1e293b;
}

.full-btn {
    width: 100%;
    margin-top: 1rem;
    background-color: #0284c7;
}

.full-btn:hover {
    background-color: #0369a1;
}

.calc-result {
    margin-top: 1.25rem;
    background: #f8fafc;
    padding: 1.1rem;
    border-radius: 10px;
    border: 1px dashed #cbd5e1;
    font-size: 0.95rem;
    color: #334155;
    line-height: 1.6;
    text-align: center;
}

.calc-result strong {
    color: #0f172a;
}