/* ========================================
   OS-Logix Public Website Styles
   Korean Flag Color Theme (#003478, #C60C30)
   ======================================== */

/* CSS Variables */
:root {
    --primary: #003478;
    --primary-dark: #002255;
    --primary-light: #0050b3;
    --accent: #C60C30;
    --accent-dark: #a00a28;
    --accent-light: #e81040;
    --white: #FFFFFF;
    --black: #1A1A1A;
    --gray-100: #F5F5F5;
    --gray-200: #E5E5E5;
    --gray-300: #D4D4D4;
    --gray-400: #A3A3A3;
    --gray-500: #737373;
    --gray-600: #525252;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--black);
    background-color: var(--white);
}

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

a:hover {
    color: var(--accent);
}

img {
    max-width: 100%;
    height: auto;
}

/* Container */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* ========================================
   HEADER / NAVIGATION
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--primary);
    z-index: 1000;
    box-shadow: var(--shadow-md);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-logo img {
    height: 40px;
}

.nav-logo span {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--white);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
}

.nav-links a:hover {
    color: var(--white);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
}

.nav-links a:hover::after {
    width: 100%;
}

.nav-cta {
    display: flex;
    align-items: center;
    gap: 1rem;
}

/* Language Selector */
.lang-selector {
    position: relative;
}

.lang-selector select {
    appearance: none;
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: var(--white);
    padding: 0.5rem 2rem 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.875rem;
}

.lang-selector select:focus {
    outline: none;
    border-color: var(--white);
}

/* Options in dropdown - need dark text for visibility */
.lang-selector select option {
    background: var(--white);
    color: var(--black);
    padding: 0.5rem;
}

.lang-selector::after {
    content: '▼';
    position: absolute;
    right: 0.75rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--white);
    font-size: 0.625rem;
    pointer-events: none;
}

/* Mobile Menu Toggle */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: var(--white);
    transition: var(--transition);
}

/* ========================================
   BUTTONS
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    transition: var(--transition);
}

.btn-primary {
    background: var(--accent);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--accent-dark);
    color: var(--white);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary);
    border: 2px solid var(--white);
}

.btn-secondary:hover {
    background: transparent;
    color: var(--white);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--white);
}

.btn-lg {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

/* ========================================
   HERO SECTION
   ======================================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding-top: 70px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'%3E%3Ccircle cx='50' cy='50' r='40' fill='none' stroke='rgba(255,255,255,0.05)' stroke-width='1'/%3E%3C/svg%3E") repeat;
    opacity: 0.5;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 600px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

/* Track Form in Hero */
.hero-track {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.hero-track-form {
    display: flex;
    gap: 1rem;
}

.hero-track-form input {
    flex: 1;
    padding: 1rem 1.5rem;
    font-size: 1rem;
    border: none;
    border-radius: 6px;
    outline: none;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

/* ========================================
   SECTIONS
   ======================================== */
.section {
    padding: 5rem 0;
}

.section-alt {
    background: var(--gray-100);
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto 3rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--black);
    margin-bottom: 1rem;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--gray-500);
}

/* ========================================
   SERVICES GRID
   ======================================== */
.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.service-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--gray-200);
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.service-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.service-icon svg {
    width: 30px;
    height: 30px;
    fill: var(--white);
}

.service-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: var(--black);
}

.service-card p {
    color: var(--gray-500);
    line-height: 1.6;
}

/* ========================================
   FEATURES
   ======================================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.feature-card {
    text-align: center;
    padding: 2rem;
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: var(--gray-100);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    transition: var(--transition);
}

.feature-card:hover .feature-icon {
    background: var(--accent);
}

.feature-card:hover .feature-icon svg {
    fill: var(--white);
}

.feature-icon svg {
    width: 40px;
    height: 40px;
    fill: var(--primary);
    transition: var(--transition);
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.feature-card p {
    color: var(--gray-500);
}

/* ========================================
   CTA SECTION
   ======================================== */
.cta-section {
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-dark) 100%);
    color: var(--white);
    text-align: center;
    padding: 4rem 0;
}

.cta-section h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.cta-section p {
    opacity: 0.9;
    margin-bottom: 2rem;
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
    background: var(--primary-dark);
    color: var(--white);
    padding: 4rem 0 2rem;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.footer-brand {
    padding-right: 1rem;
}

.footer-logo-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    margin-bottom: 0.75rem;
}

.footer-logo {
    height: 45px;
    width: auto;
    object-fit: contain;
}

.footer-company-name {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--white);
}

.footer-tagline {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
    margin: 0;
    line-height: 1.5;
}

.footer h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--white);
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.75rem;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.7);
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    font-size: 0.875rem;
}

.footer-links a:hover {
    color: var(--white);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    text-align: center;
    font-size: 0.875rem;
    opacity: 0.7;
}

/* ========================================
   PAGE HEADER
   ======================================== */
.page-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 8rem 0 4rem;
    text-align: center;
}

.page-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.page-header p {
    opacity: 0.9;
    font-size: 1.125rem;
}

/* ========================================
   FORMS
   ======================================== */
.form-group {
    margin-bottom: 1.5rem;
}

.form-label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--black);
}

.form-input,
.form-textarea,
.form-select {
    width: 100%;
    padding: 0.875rem 1rem;
    font-size: 1rem;
    border: 1px solid var(--gray-300);
    border-radius: 6px;
    transition: var(--transition);
    font-family: inherit;
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0, 52, 120, 0.1);
}

.form-textarea {
    min-height: 150px;
    resize: vertical;
}

/* ========================================
   CARDS
   ======================================== */
.card {
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--gray-200);
    overflow: hidden;
}

.card-body {
    padding: 1.5rem;
}

/* ========================================
   ALERTS
   ======================================== */
.alert {
    padding: 1rem 1.5rem;
    border-radius: 6px;
    margin-bottom: 1.5rem;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 992px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--primary);
        flex-direction: column;
        padding: 1rem;
        gap: 0;
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        width: 100%;
    }

    .nav-links a {
        display: block;
        padding: 1rem;
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }

    .nav-toggle {
        display: flex;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-track-form {
        flex-direction: column;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }
}