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

:root {
    --primary: #0066ff;
    --primary-hover: #0052cc;
    --primary-light: #e6f0ff;
    --bg: #ffffff;
    --bg-secondary: #fafbfc;
    --bg-tertiary: #f5f7fa;
    --text: #1a1a1a;
    --text-secondary: #6b6b6b;
    --text-tertiary: #9b9b9b;
    --border: #e8e8e8;
    --border-light: #f0f0f0;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', Roboto, 'Helvetica Neue', sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 2px 8px rgba(0, 102, 255, 0.2);
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(0, 102, 255, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-outline {
    background: transparent;
    border: 1.5px solid var(--border);
    color: var(--text);
}

.btn-outline:hover {
    background: var(--bg-secondary);
    border-color: var(--text-secondary);
}

.btn-lg {
    padding: 16px 40px;
    font-size: 17px;
    border-radius: var(--radius-lg);
}

.btn-full {
    width: 100%;
    text-align: center;
}

/* Header */
.header {
    border-bottom: 1px solid var(--border-light);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav {
    max-width: 1280px;
    margin: 0 auto;
    padding: 20px 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-size: 22px;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-links a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
}

.nav-links a:hover {
    color: var(--text);
    background: var(--bg-tertiary);
}

.nav-links .btn {
    margin-left: 4px;
}

.nav-links .btn-primary {
    color: #fff;
}

.nav-links .btn-primary:hover {
    color: #fff;
}

/* Hero */
.hero {
    text-align: center;
    padding: 120px 32px 140px;
    background: linear-gradient(180deg, var(--bg) 0%, var(--bg-secondary) 100%);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(0, 102, 255, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.hero h1 {
    font-size: 64px;
    font-weight: 700;
    margin-bottom: 24px;
    line-height: 1.1;
    letter-spacing: -1.5px;
    color: var(--text);
    position: relative;
}

.hero p {
    font-size: 21px;
    color: var(--text-secondary);
    margin-bottom: 40px;
    line-height: 1.5;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    position: relative;
}

/* Features */
.features {
    max-width: 1280px;
    margin: 0 auto;
    padding: 100px 32px;
    text-align: center;
}

.features h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 64px;
    letter-spacing: -1px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.feature-card {
    padding: 40px 32px;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    text-align: left;
    background: var(--bg);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.feature-card h3 {
    margin-bottom: 12px;
    font-size: 22px;
    font-weight: 600;
    letter-spacing: -0.3px;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 16px;
    line-height: 1.6;
}

/* Pricing */
.pricing {
    background: var(--bg-tertiary);
    padding: 100px 32px;
    text-align: center;
}

.pricing h2 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 64px;
    letter-spacing: -1px;
}

.pricing-grid {
    max-width: 900px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.pricing-card {
    background: var(--bg);
    padding: 48px 40px;
    border: 2px solid var(--border-light);
    border-radius: var(--radius-lg);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.pricing-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.pricing-card.featured {
    border-color: var(--primary);
    box-shadow: 0 8px 32px rgba(0, 102, 255, 0.15);
}

.pricing-card.featured::before {
    content: '인기';
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    padding: 6px 20px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
}

.pricing-card h3 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 12px;
    letter-spacing: -0.3px;
}

.price {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 32px;
    letter-spacing: -1px;
}

.price span {
    font-size: 18px;
    font-weight: 500;
    color: var(--text-secondary);
}

.pricing-card ul {
    margin-bottom: 32px;
    text-align: left;
}

.pricing-card li {
    padding: 14px 0;
    font-size: 16px;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-light);
    position: relative;
    padding-left: 28px;
}

.pricing-card li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: 700;
}

/* Auth Pages */
.auth-page {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: calc(100vh - 65px);
    background: linear-gradient(135deg, var(--bg-tertiary) 0%, var(--bg-secondary) 100%);
}

.auth-card {
    background: var(--bg);
    padding: 48px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-md);
    width: 100%;
    max-width: 440px;
}

.auth-card h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 32px;
    text-align: center;
    letter-spacing: -0.5px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text);
}

.form-group input {
    width: 100%;
    padding: 14px 16px;
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    font-size: 16px;
    outline: none;
    transition: all 0.2s;
    font-family: inherit;
}

.form-group input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
}

.auth-card .btn {
    margin-top: 12px;
}

.auth-link {
    text-align: center;
    margin-top: 24px;
    font-size: 15px;
    color: var(--text-secondary);
}

.auth-link a {
    color: var(--primary);
    font-weight: 600;
    text-decoration: none;
}

.auth-link a:hover {
    text-decoration: underline;
}

/* Footer */
.footer {
    text-align: center;
    padding: 40px 32px;
    font-size: 15px;
    color: var(--text-tertiary);
    border-top: 1px solid var(--border-light);
    background: var(--bg-secondary);
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        padding: 80px 24px 100px;
    }

    .hero h1 {
        font-size: 40px;
        letter-spacing: -1px;
    }

    .hero p {
        font-size: 18px;
    }

    .nav {
        padding: 16px 24px;
    }

    .nav-links {
        gap: 4px;
    }

    .nav-links a:not(.btn) {
        display: none;
    }

    .features,
    .pricing {
        padding: 60px 24px;
    }

    .features h2,
    .pricing h2 {
        font-size: 36px;
        margin-bottom: 40px;
    }

    .feature-grid,
    .pricing-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }

    .auth-card {
        padding: 32px 24px;
    }

    .auth-card h1 {
        font-size: 28px;
    }
}