/* ===========================
   MidPay Premium Design System
   Apple-Inspired Minimalism
   =========================== */

:root {
    /* Premium Color Palette */
    --black: #000000;
    --near-black: #0F0F0F;
    --charcoal: #1A1A1A;
    --dark-gray: #2E2E2E;
    --mid-gray: #6E6E73;
    --light-gray: #D2D2D7;
    --off-white: #F5F5F7;
    --white: #FFFFFF;
    
    /* Accent Colors */
    --accent-primary: #A4D233;
    --accent-blue: #0071E3;
    --accent-purple: #5E5CE6;
    
    /* Status */
    --success: #30D158;
    --error: #FF453A;
    
    /* Typography - SF Pro Display inspired */
    --font-primary: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Inter', 'Segoe UI', sans-serif;
    
    /* Premium Spacing System (8px base) */
    --space-1: 0.5rem;   /* 8px */
    --space-2: 1rem;     /* 16px */
    --space-3: 1.5rem;   /* 24px */
    --space-4: 2rem;     /* 32px */
    --space-5: 2.5rem;   /* 40px */
    --space-6: 3rem;     /* 48px */
    --space-8: 4rem;     /* 64px */
    --space-10: 5rem;    /* 80px */
    --space-12: 6rem;    /* 96px */
    --space-16: 8rem;    /* 128px */
    --space-20: 10rem;   /* 160px */
    
    /* Premium Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);
    
    /* Border Radius - Subtle curves */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions - Smooth & slow */
    --ease: cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: 200ms var(--ease);
    --transition-base: 400ms var(--ease);
    --transition-slow: 600ms var(--ease);
}

/* ===========================
   Premium Reset
   =========================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    font-size: 1rem;
    line-height: 1.5;
    color: var(--near-black);
    background: var(--white);
    letter-spacing: -0.01em;
}

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

/* ===========================
   Premium Typography
   =========================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.1;
    letter-spacing: -0.03em;
    color: var(--black);
}

h1 {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 700;
    letter-spacing: -0.04em;
}

h2 {
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 600;
}

h3 {
    font-size: clamp(1.5rem, 3vw, 2.5rem);
    font-weight: 600;
}

p {
    font-size: 1.125rem;
    line-height: 1.6;
    color: var(--mid-gray);
}

.text-xl {
    font-size: clamp(1.25rem, 2vw, 1.5rem);
    line-height: 1.5;
}

.text-sm {
    font-size: 0.875rem;
    line-height: 1.4;
}

/* ===========================
   Premium Layout
   =========================== */

.section {
    padding: var(--space-16) 0;
}

.section-sm {
    padding: var(--space-12) 0;
}

.section-lg {
    padding: var(--space-20) 0;
}

.container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 max(var(--space-4), calc((100vw - 1440px) / 2 + var(--space-4)));
}

.container-narrow {
    max-width: 980px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

.container-wide {
    max-width: 1920px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

/* ===========================
   Premium Navigation
   =========================== */

.nav-premium {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: saturate(180%) blur(20px);
    -webkit-backdrop-filter: saturate(180%) blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.nav-content-premium {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 44px;
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 var(--space-3);
}

.logo-premium {
    height: 24px;
    display: flex;
    align-items: center;
}

.logo-premium img {
    height: 24px;
    width: auto;
}

.nav-links-premium {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    list-style: none;
}

.nav-links-premium a {
    font-size: 0.75rem;
    font-weight: 400;
    color: var(--near-black);
    text-decoration: none;
    opacity: 0.8;
    transition: opacity var(--transition-fast);
    letter-spacing: 0.01em;
}

.nav-links-premium a:hover {
    opacity: 1;
}

.nav-cta-premium {
    background: var(--accent-primary);
    color: var(--white) !important;
    padding: var(--space-1) var(--space-2);
    border-radius: var(--radius-xl);
    font-weight: 500;
    opacity: 1 !important;
}

/* ===========================
   Premium Hero
   =========================== */

.hero-premium {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: var(--space-20) var(--space-4);
    background: linear-gradient(180deg, var(--white) 0%, var(--off-white) 100%);
    position: relative;
    overflow: hidden;
}

.hero-premium::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -25%;
    width: 150%;
    height: 150%;
    background: radial-gradient(circle, rgba(0, 212, 170, 0.03) 0%, transparent 70%);
    pointer-events: none;
}

.hero-content-premium {
    max-width: 980px;
    margin: 0 auto;
    position: relative;
    z-index: 1;
}

.eyebrow {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--accent-primary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-3);
}

.hero-headline {
    margin-bottom: var(--space-4);
    background: linear-gradient(135deg, var(--black) 0%, var(--dark-gray) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subheadline {
    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
    line-height: 1.4;
    color: var(--mid-gray);
    margin-bottom: var(--space-8);
    max-width: 720px;
    margin-left: auto;
    margin-right: auto;
}

/* ===========================
   Premium Buttons
   =========================== */

.btn-premium {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-1);
    padding: var(--space-2) var(--space-4);
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-xl);
    text-decoration: none;
    transition: all var(--transition-base);
    cursor: pointer;
    border: none;
    letter-spacing: -0.01em;
}

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

.btn-premium-primary:hover {
    background: var(--charcoal);
    transform: translateY(-1px);
    box-shadow: var(--shadow-lg);
}

.btn-premium-secondary {
    background: transparent;
    color: var(--accent-primary);
    border: 1.5px solid var(--accent-primary);
}

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

.btn-premium-large {
    padding: var(--space-3) var(--space-6);
    font-size: 1.0625rem;
}

.cta-group {
    display: flex;
    gap: var(--space-3);
    justify-content: center;
    flex-wrap: wrap;
}

/* ===========================
   Premium Cards
   =========================== */

.card-premium {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: var(--space-6);
    transition: all var(--transition-base);
    border: 1px solid transparent;
}

.card-premium:hover {
    box-shadow: var(--shadow-xl);
    border-color: rgba(0, 0, 0, 0.06);
    transform: translateY(-4px);
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--space-4);
}

.card-grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(480px, 1fr));
}

.card-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--off-white);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-3);
    font-size: 1.5rem;
    color: var(--accent-primary);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--black);
    margin-bottom: var(--space-2);
}

.card-description {
    font-size: 1rem;
    line-height: 1.6;
    color: var(--mid-gray);
}

/* ===========================
   Premium Stats
   =========================== */

.stats-premium {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-8);
    text-align: center;
    padding: var(--space-12) 0;
}

.stat-premium {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.stat-value {
    font-size: clamp(3rem, 5vw, 4.5rem);
    font-weight: 700;
    line-height: 1;
    letter-spacing: -0.04em;
    background: linear-gradient(135deg, var(--black) 0%, var(--mid-gray) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.9375rem;
    color: var(--mid-gray);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-weight: 500;
}

/* ===========================
   Premium Calculator
   =========================== */

.calculator-premium {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-xl);
    max-width: 980px;
    margin: 0 auto;
}

.calculator-header {
    text-align: center;
    margin-bottom: var(--space-8);
}

.calculator-inputs {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-4);
    margin-bottom: var(--space-8);
}

.input-premium {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.input-premium label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--mid-gray);
    letter-spacing: 0.01em;
}

.input-premium input {
    padding: var(--space-3);
    font-size: 1.5rem;
    font-weight: 600;
    font-family: var(--font-primary);
    color: var(--black);
    background: var(--off-white);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    letter-spacing: -0.01em;
}

.input-premium input:focus {
    outline: none;
    border-color: var(--accent-primary);
    background: var(--white);
}

.calculator-results {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-4);
    padding: var(--space-6);
    background: var(--off-white);
    border-radius: var(--radius-lg);
}

.result-premium {
    text-align: center;
}

.result-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--mid-gray);
    margin-bottom: var(--space-1);
    font-weight: 600;
}

.result-value {
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1;
    letter-spacing: -0.02em;
}

.result-value.negative {
    color: var(--error);
}

.result-value.positive {
    color: var(--success);
}

.savings-highlight {
    grid-column: 1 / -1;
    text-align: center;
    padding: var(--space-4);
    background: linear-gradient(135deg, var(--accent-primary) 0%, var(--accent-blue) 100%);
    border-radius: var(--radius-md);
    color: var(--white);
}

.savings-highlight .result-value {
    font-size: 3.5rem;
    color: var(--white);
}

/* ===========================
   Premium Divider
   =========================== */

.divider {
    height: 1px;
    background: linear-gradient(90deg, transparent 0%, rgba(0, 0, 0, 0.08) 50%, transparent 100%);
    margin: var(--space-12) 0;
}

/* ===========================
   Premium Footer
   =========================== */

.footer-premium {
    background: var(--near-black);
    color: var(--light-gray);
    padding: var(--space-12) 0 var(--space-6);
}

.footer-grid-premium {
    display: grid;
    grid-template-columns: 2fr repeat(4, 1fr);
    gap: var(--space-8);
    margin-bottom: var(--space-8);
}

.footer-col-premium h4 {
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--white);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-3);
}

.footer-col-premium ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.footer-col-premium a {
    color: var(--light-gray);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color var(--transition-fast);
    opacity: 0.8;
}

.footer-col-premium a:hover {
    color: var(--white);
    opacity: 1;
}

.footer-bottom-premium {
    text-align: center;
    padding-top: var(--space-6);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.75rem;
    color: var(--mid-gray);
}

/* ===========================
   Responsive Design
   =========================== */

@media (max-width: 1024px) {
    .card-grid-2 {
        grid-template-columns: 1fr;
    }
    
    .footer-grid-premium {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --space-16: 6rem;
        --space-20: 8rem;
    }
    
    .hero-premium {
        min-height: auto;
        padding: var(--space-16) var(--space-3);
    }
    
    .nav-links-premium {
        display: none;
    }
    
    .calculator-premium {
        padding: var(--space-6);
    }
    
    .calculator-inputs {
        grid-template-columns: 1fr;
    }
    
    .footer-grid-premium {
        grid-template-columns: 1fr;
    }
    
    .cta-group {
        flex-direction: column;
    }
    
    .btn-premium {
        width: 100%;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 2.5rem;
    }
    
    h2 {
        font-size: 2rem;
    }
    
    .stat-value {
        font-size: 2.5rem;
    }
}