/* ============================================
   KidMarket – Refined Flat Design System
   Mobile-first, Swiss-inspired precision
   ============================================ */

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

:root {
    /* Color Palette – Restrained & Cohesive */
    --color-primary: #2563eb;
    --color-primary-dark: #1e40af;
    --color-success: #059669;
    --color-danger: #dc2626;
    --color-neutral-900: #0f172a;
    --color-neutral-800: #1e293b;
    --color-neutral-700: #334155;
    --color-neutral-600: #475569;
    --color-neutral-400: #94a3b8;
    --color-neutral-300: #cbd5e1;
    --color-neutral-200: #e2e8f0;
    --color-neutral-100: #f1f5f9;
    --color-neutral-50: #f8fafc;
    --color-white: #ffffff;

    /* Typography – Modern & Precise */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Helvetica Neue", Arial, sans-serif;
    --font-weight-regular: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    /* Spacing System – Consistent & Generous */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    /* Layout */
    --container-max: 1200px;
    --border-radius: 12px;
    --border-radius-sm: 8px;
    
    /* Transitions – Smooth & Purposeful */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-sans);
    font-weight: var(--font-weight-regular);
    line-height: 1.6;
    color: var(--color-neutral-900);
    background-color: var(--color-neutral-50);
}

/* === Typography Scale === */
.logo {
    font-size: 1.25rem;
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.02em;
    color: var(--color-neutral-900);
}

.intro-title {
    font-size: 2rem;
    font-weight: var(--font-weight-bold);
    letter-spacing: -0.03em;
    line-height: 1.1;
    color: var(--color-neutral-900);
}

.intro-text {
    font-size: 1.125rem;
    font-weight: var(--font-weight-regular);
    color: var(--color-neutral-600);
    line-height: 1.6;
}

.section-title {
    font-size: 1.5rem;
    font-weight: var(--font-weight-semibold);
    letter-spacing: -0.02em;
    color: var(--color-neutral-900);
}

/* === Layout === */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--space-5);
    padding-right: var(--space-5);
}

@media (min-width: 768px) {
    .container {
        padding-left: var(--space-8);
        padding-right: var(--space-8);
    }
}

/* === Header === */
.header {
    position: sticky;
    top: 0;
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-neutral-200);
    z-index: 100;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.coin-display {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-4);
    background-color: var(--color-neutral-100);
    border-radius: var(--border-radius-sm);
}

.coin-icon {
    font-size: 1.25rem;
    line-height: 1;
}

.coin-amount {
    font-size: 1rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-neutral-900);
}

/* === Main Content === */
.main {
    min-height: calc(100vh - 4rem);
}

.intro {
    padding-top: var(--space-12);
    padding-bottom: var(--space-8);
    text-align: center;
}

.intro-title {
    margin-bottom: var(--space-3);
}

/* === Markets Grid === */
.markets {
    padding-bottom: var(--space-16);
}

.market-grid {
    display: grid;
    gap: var(--space-4);
    grid-template-columns: 1fr;
}

@media (min-width: 640px) {
    .market-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--space-5);
    }
}

@media (min-width: 1024px) {
    .market-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--space-6);
    }
}

.market-card {
    background-color: var(--color-white);
    border: 1px solid var(--color-neutral-200);
    border-radius: var(--border-radius);
    padding: var(--space-6);
    cursor: pointer;
    transition: all var(--transition-base);
}

.market-card:hover {
    border-color: var(--color-neutral-300);
    transform: translateY(-2px);
}

.market-card:active {
    transform: translateY(0);
}

.market-category {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: var(--font-weight-medium);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    margin-bottom: var(--space-3);
}

.market-question {
    font-size: 1.125rem;
    font-weight: var(--font-weight-semibold);
    line-height: 1.4;
    color: var(--color-neutral-900);
    margin-bottom: var(--space-5);
}

.market-stats {
    display: flex;
    gap: var(--space-4);
    padding-top: var(--space-4);
    border-top: 1px solid var(--color-neutral-100);
}

.stat {
    flex: 1;
}

.stat-label {
    display: block;
    font-size: 0.75rem;
    font-weight: var(--font-weight-medium);
    color: var(--color-neutral-600);
    margin-bottom: var(--space-1);
}

.stat-value {
    display: block;
    font-size: 1.25rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-neutral-900);
}

.stat-value.yes {
    color: var(--color-success);
}

.stat-value.no {
    color: var(--color-danger);
}

/* === Progress Bar === */
.progress-bar {
    height: 4px;
    background-color: var(--color-neutral-100);
    border-radius: 2px;
    overflow: hidden;
    margin-bottom: var(--space-4);
}

.progress-fill {
    height: 100%;
    background-color: var(--color-success);
    transition: width var(--transition-base);
}

/* === How It Works Section === */
.how-it-works {
    padding-top: var(--space-16);
    padding-bottom: var(--space-20);
    background-color: var(--color-white);
    border-top: 1px solid var(--color-neutral-200);
}

.how-it-works .section-title {
    text-align: center;
    margin-bottom: var(--space-10);
}

.steps-grid {
    display: grid;
    gap: var(--space-8);
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .steps-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: var(--space-6);
    }
}

.step {
    text-align: center;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 3rem;
    height: 3rem;
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    background-color: var(--color-neutral-100);
    border-radius: 50%;
    margin-bottom: var(--space-4);
}

.step-title {
    font-size: 1.125rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-neutral-900);
    margin-bottom: var(--space-2);
}

.step-text {
    font-size: 0.9375rem;
    color: var(--color-neutral-600);
    line-height: 1.6;
}

/* === Modal === */
.modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--space-4);
}

.modal.active {
    display: flex;
}

.modal-overlay {
    position: absolute;
    inset: 0;
    background-color: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(2px);
}

.modal-content {
    position: relative;
    width: 100%;
    max-width: 28rem;
    background-color: var(--color-white);
    border-radius: var(--border-radius);
    padding: var(--space-8);
    animation: modalSlideUp var(--transition-base);
}

@keyframes modalSlideUp {
    from {
        opacity: 0;
        transform: translateY(1rem);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-close {
    position: absolute;
    top: var(--space-4);
    right: var(--space-4);
    width: 2rem;
    height: 2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    line-height: 1;
    color: var(--color-neutral-600);
    background: none;
    border: none;
    cursor: pointer;
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.modal-close:hover {
    background-color: var(--color-neutral-100);
    color: var(--color-neutral-900);
}

.modal-title {
    font-size: 0.75rem;
    font-weight: var(--font-weight-medium);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    margin-bottom: var(--space-2);
}

.modal-question {
    font-size: 1.25rem;
    font-weight: var(--font-weight-semibold);
    line-height: 1.4;
    color: var(--color-neutral-900);
    margin-bottom: var(--space-8);
}

/* === Vote Options === */
.vote-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-3);
    margin-bottom: var(--space-6);
}

.vote-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-5);
    font-family: inherit;
    background-color: var(--color-neutral-50);
    border: 2px solid var(--color-neutral-200);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.vote-btn:hover {
    border-color: var(--color-neutral-300);
}

.vote-btn.selected {
    background-color: var(--color-neutral-900);
}

.vote-btn-yes.selected {
    background-color: var(--color-success);
    border-color: var(--color-success);
}

.vote-btn-no.selected {
    background-color: var(--color-danger);
    border-color: var(--color-danger);
}

.vote-btn.selected .vote-label,
.vote-btn.selected .vote-percent {
    color: var(--color-white);
}

.vote-label {
    font-size: 1rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-neutral-900);
}

.vote-percent {
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
    color: var(--color-neutral-700);
}

/* === Form Elements === */
.coin-input {
    margin-bottom: var(--space-6);
}

.input-label {
    display: block;
    font-size: 0.875rem;
    font-weight: var(--font-weight-medium);
    color: var(--color-neutral-700);
    margin-bottom: var(--space-2);
}

.input-field {
    width: 100%;
    padding: var(--space-3) var(--space-4);
    font-family: inherit;
    font-size: 1rem;
    color: var(--color-neutral-900);
    background-color: var(--color-white);
    border: 1px solid var(--color-neutral-300);
    border-radius: var(--border-radius-sm);
    transition: border-color var(--transition-fast);
}

.input-field:focus {
    outline: none;
    border-color: var(--color-primary);
}

/* === Buttons === */
.submit-btn {
    width: 100%;
    padding: var(--space-4) var(--space-6);
    font-family: inherit;
    font-size: 1rem;
    font-weight: var(--font-weight-semibold);
    color: var(--color-white);
    background-color: var(--color-primary);
    border: none;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.submit-btn:hover {
    background-color: var(--color-primary-dark);
}

.submit-btn:active {
    transform: scale(0.98);
}

.submit-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* === Utility Classes === */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}