/* ==================================================
   Common Styles - Modern Minimalist Theme
   ใช้ได้ทุกหน้า สไตล์ clean และ modern
   ================================================== */

:root {
    /* Colors - Monochrome with subtle accents */
    --color-primary: #000000;
    --color-secondary: #2c2c2c;
    --color-accent: #404040;
    --color-text: #1a1a1a;
    --color-text-light: #666666;
    --color-text-muted: #999999;
    --color-background: #fafafa;
    --color-white: #ffffff;
    --color-border: #e0e0e0;
    --color-error: #d32f2f;
    --color-success: #2e7d32;

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

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

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

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-sm);
}

/* Buttons - Modern Clean Style */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 0.9375rem;
    font-weight: 500;
    line-height: 1.5;
    text-align: center;
    text-decoration: none;
    white-space: nowrap;
    vertical-align: middle;
    cursor: pointer;
    user-select: none;
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    transition: all var(--transition-base);
    outline: none;
}

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

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

.btn-primary:hover:not(:disabled) {
    background-color: var(--color-secondary);
    border-color: var(--color-secondary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

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

.btn-secondary:hover:not(:disabled) {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.btn-block {
    display: block;
    width: 100%;
}

/* Forms - Clean Input Style */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-xs);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text);
}

.form-control {
    display: block;
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 0.9375rem;
    font-weight: 400;
    line-height: 1.5;
    color: var(--color-text);
    background-color: var(--color-white);
    background-clip: padding-box;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    outline: none;
}

.form-control:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(0, 0, 0, 0.05);
}

.form-control::placeholder {
    color: var(--color-text-muted);
}

/* Cards */
.card {
    background-color: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transition: box-shadow var(--transition-base);
}

.card:hover {
    box-shadow: var(--shadow-lg);
}

.card-body {
    padding: var(--spacing-lg);
}

/* Alerts */
.alert {
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-md);
    border: 1px solid transparent;
    border-radius: var(--radius-md);
    font-size: 0.875rem;
}

.alert-danger {
    color: #842029;
    background-color: #f8d7da;
    border-color: #f5c2c7;
}

.alert-success {
    color: #0f5132;
    background-color: #d1e7dd;
    border-color: #badbcc;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-muted { color: var(--color-text-muted); }
.text-primary { color: var(--color-primary); }

.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }

.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }

.d-block { display: block; }
.d-flex { display: flex; }
.d-grid { display: grid; }

/* Spinner/Loading */
.spinner-border {
    display: inline-block;
    width: 1rem;
    height: 1rem;
    vertical-align: text-bottom;
    border: 0.15em solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: spinner-border 0.75s linear infinite;
}

.spinner-border-sm {
    width: 0.875rem;
    height: 0.875rem;
    border-width: 0.125em;
}

@keyframes spinner-border {
    to { transform: rotate(360deg); }
}

/* Responsive */
@media (max-width: 768px) {
    :root {
        --spacing-lg: 1.5rem;
        --spacing-xl: 2rem;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
}