/* ===================================
   CSS Variables & Design System
   =================================== */
:root {
    /* Colors - School Blue and Gold palette */
    --color-primary: #1e3a5f;
    --color-primary-dark: #0f2744;
    --color-primary-light: #2c5282;
    --color-accent: #d69e2e;
    --color-accent-dark: #b7791f;

    /* Neutral colors */
    --color-bg: #f8fafc;
    --color-surface: #ffffff;
    --color-surface-hover: #f1f5f9;
    --color-border: #e2e8f0;
    --color-border-focus: #1a5f7a;

    /* Text colors - High contrast for readability */
    --color-text: #1e293b;
    --color-text-muted: #475569;
    --color-text-light: #64748b;
    --color-text-inverse: #ffffff;

    /* Semantic colors */
    --color-success: #1e3a5f;
    --color-success-bg: #ebf4ff;
    --color-error: #dc2626;
    --color-error-bg: #fef2f2;
    --color-warning: #d97706;
    --color-warning-bg: #fffbeb;
    --color-info: #1e3a5f;
    --color-info-bg: #ebf4ff;

    /* Typography - Large, readable sizes */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.875rem;
    /* 14px */
    --font-size-sm: 1rem;
    /* 16px */
    --font-size-base: 1.125rem;
    /* 18px - Larger base for elderly */
    --font-size-lg: 1.25rem;
    /* 20px */
    --font-size-xl: 1.5rem;
    /* 24px */
    --font-size-2xl: 1.875rem;
    /* 30px */
    --font-size-3xl: 2.25rem;
    /* 36px */
    --font-size-4xl: 3rem;
    /* 48px */

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;

    /* Border radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text);
    background: linear-gradient(135deg, #1e3a5f 0%, #2c5282 100%);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===================================
   Layout
   =================================== */
.container {
    max-width: 700px;
    margin: 0 auto;
    padding: var(--space-lg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ===================================
   Header
   =================================== */
.header {
    text-align: center;
    margin-bottom: var(--space-xl);
    padding: var(--space-xl) 0;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-md);
    margin-bottom: var(--space-sm);
}

.logo-icon {
    width: 48px;
    height: 48px;
    color: var(--color-text-inverse);
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.header h1 {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--color-text-inverse);
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.subtitle {
    font-size: var(--font-size-xl);
    color: rgba(255, 255, 255, 0.9);
    font-weight: 500;
}

/* ===================================
   Cards (Common Styles)
   =================================== */
.intro-card,
.calculator-card,
.results-card,
.error-card {
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    padding: var(--space-xl);
    margin-bottom: var(--space-lg);
    box-shadow: var(--shadow-xl);
}

/* ===================================
   Intro Card
   =================================== */
.intro-card h2 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--space-md);
}

.intro-card p {
    color: var(--color-text-muted);
    margin-bottom: var(--space-lg);
}

.rate-info {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md);
    background: var(--color-info-bg);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-info);
}

.rate-label {
    font-weight: 600;
    color: var(--color-primary);
}

.rate-value {
    color: var(--color-text);
    font-weight: 500;
}

/* ===================================
   Calculator Form
   =================================== */
.calculator-form {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.input-label {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text);
}

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

.address-input {
    width: 100%;
    padding: var(--space-lg);
    font-size: var(--font-size-lg);
    font-family: var(--font-family);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
    color: var(--color-text);
    transition: border-color var(--transition-base), box-shadow var(--transition-base);
}

.address-input::placeholder {
    color: var(--color-text-light);
}

.address-input:hover {
    border-color: var(--color-text-light);
}

.address-input:focus {
    outline: none;
    border-color: var(--color-border-focus);
    box-shadow: 0 0 0 4px rgba(30, 58, 95, 0.15);
}

.calculate-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    width: 100%;
    padding: var(--space-lg) var(--space-xl);
    font-size: var(--font-size-lg);
    font-weight: 600;
    font-family: var(--font-family);
    color: var(--color-text-inverse);
    background: linear-gradient(135deg, var(--color-accent) 0%, var(--color-accent-dark) 100%);
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    box-shadow: var(--shadow-md);
    min-height: 60px;
    /* Large touch target for elderly */
}

.calculate-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.calculate-btn:disabled {
    cursor: not-allowed;
    opacity: 0.7;
    transform: none;
}

.btn-loading {
    display: none;
    /* Hidden by default, shown via JS */
    align-items: center;
}

.calculate-btn:disabled .btn-loading {
    display: flex;
    /* Show when button is disabled (loading) */
}

.calculate-btn:disabled .btn-text {
    display: none;
    /* Hide text when loading */
}

.spinner {
    width: 24px;
    height: 24px;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    from {
        transform: rotate(0deg);
    }

    to {
        transform: rotate(360deg);
    }
}

.input-hint {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
}

/* ===================================
   Results Card
   =================================== */
.results-card {
    background: linear-gradient(135deg, var(--color-success-bg) 0%, #d1fae5 100%);
    border: 2px solid var(--color-success);
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-lg);
}

.results-icon {
    width: 40px;
    height: 40px;
    color: var(--color-success);
}

.results-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-success);
}

.results-address {
    font-size: var(--font-size-base);
    color: var(--color-text-muted);
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid rgba(5, 150, 105, 0.2);
}

.results-grid {
    display: grid;
    gap: var(--space-lg);
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    padding: var(--space-md);
    background: rgba(255, 255, 255, 0.7);
    border-radius: var(--radius-md);
}

.result-label {
    font-size: var(--font-size-base);
    color: var(--color-text-muted);
}

.result-value {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--color-text);
}

.result-item.highlight {
    background: var(--color-success);
    padding: var(--space-lg);
}

.result-item.highlight .result-label,
.result-item.highlight .result-value {
    color: var(--color-text-inverse);
}

.result-item.highlight .result-value {
    font-size: var(--font-size-2xl);
}

.monthly-note {
    margin-top: var(--space-lg);
    padding: var(--space-md);
    background: rgba(255, 255, 255, 0.7);
    border-radius: var(--radius-md);
    text-align: center;
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
}

.monthly-amount {
    font-weight: 600;
    color: var(--color-text);
}

/* ===================================
   Error Card
   =================================== */
.error-card {
    background: var(--color-error-bg);
    border: 2px solid var(--color-error);
    animation: shake 0.5s ease-out;
}

@keyframes shake {

    0%,
    100% {
        transform: translateX(0);
    }

    10%,
    30%,
    50%,
    70%,
    90% {
        transform: translateX(-5px);
    }

    20%,
    40%,
    60%,
    80% {
        transform: translateX(5px);
    }
}

.error-header {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-bottom: var(--space-md);
}

.error-icon {
    width: 40px;
    height: 40px;
    color: var(--color-error);
}

.error-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-error);
}

.error-message {
    color: var(--color-text);
    font-size: var(--font-size-base);
}

.error-hint {
    margin-top: var(--space-md);
    padding: var(--space-md);
    background: rgba(255, 255, 255, 0.7);
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}

/* Info card (for non-district properties) */
.info-card {
    background: var(--color-warning-bg);
    border: 2px solid var(--color-warning);
}

.info-card .error-icon,
.info-card .error-title {
    color: var(--color-warning);
}

/* ===================================
   Footer
   =================================== */
.footer {
    margin-top: auto;
    padding-top: var(--space-xl);
}

.footer-content {
    text-align: center;
    padding: var(--space-lg);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(10px);
}

.data-source {
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: var(--space-sm);
}

.data-source a {
    color: var(--color-text-inverse);
    font-weight: 500;
}

.disclaimer {
    font-size: var(--font-size-xs);
    color: rgba(255, 255, 255, 0.7);
}

/* ===================================
   Responsive Design
   =================================== */
@media (min-width: 600px) {
    .input-wrapper {
        flex-direction: row;
    }

    .calculate-btn {
        width: auto;
        flex-shrink: 0;
    }
}

@media (max-width: 480px) {
    .container {
        padding: var(--space-md);
    }

    .header h1 {
        font-size: var(--font-size-xl);
    }

    .logo-icon {
        width: 36px;
        height: 36px;
    }

    .intro-card,
    .calculator-card,
    .results-card,
    .error-card {
        padding: var(--space-lg);
    }

    .result-item {
        flex-direction: column;
        gap: var(--space-xs);
    }

    .result-item.highlight {
        text-align: center;
    }
}

/* ===================================
   Accessibility
   =================================== */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus visible for keyboard navigation */
:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
}