/* =====================================================
   TextCrypt — CSS Design System
   Dark/Light theme via CSS custom properties on :root
   ===================================================== */

/* ---- Theme tokens ---- */
:root,
[data-theme="dark"] {
    --bg:           #0d1117;
    --bg-gradient:  linear-gradient(135deg, #0d1117 0%, #161b22 50%, #0d1117 100%);
    --surface:      rgba(22, 27, 34, 0.85);
    --surface-2:    rgba(33, 38, 45, 0.9);
    --border:       rgba(48, 54, 61, 0.8);
    --border-focus: #58a6ff;
    --text:         #e6edf3;
    --text-muted:   #8b949e;
    --accent:       #58a6ff;
    --accent-hover: #79b8ff;
    --accent-dim:   rgba(88, 166, 255, 0.12);
    --btn-secondary-bg: rgba(33, 38, 45, 0.9);
    --btn-secondary-border: rgba(88, 166, 255, 0.4);
    --error-bg:     rgba(248, 81, 73, 0.12);
    --error-border: rgba(248, 81, 73, 0.5);
    --error-text:   #ffa198;
    --header-bg:    rgba(13, 17, 23, 0.92);
    --footer-bg:    rgba(13, 17, 23, 0.85);
    --shadow:       0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-sm:    0 2px 8px rgba(0, 0, 0, 0.35);
    --scrollbar-track: #161b22;
    --scrollbar-thumb: #30363d;
}

[data-theme="light"] {
    --bg:           #f0f4f8;
    --bg-gradient:  linear-gradient(135deg, #e8edf3 0%, #f0f4f8 50%, #e8edf3 100%);
    --surface:      rgba(255, 255, 255, 0.92);
    --surface-2:    rgba(246, 248, 250, 0.95);
    --border:       rgba(208, 215, 222, 0.85);
    --border-focus: #0969da;
    --text:         #1c2128;
    --text-muted:   #57606a;
    --accent:       #0969da;
    --accent-hover: #0550ae;
    --accent-dim:   rgba(9, 105, 218, 0.08);
    --btn-secondary-bg: rgba(246, 248, 250, 0.95);
    --btn-secondary-border: rgba(9, 105, 218, 0.35);
    --error-bg:     rgba(207, 34, 46, 0.08);
    --error-border: rgba(207, 34, 46, 0.4);
    --error-text:   #cf222e;
    --header-bg:    rgba(255, 255, 255, 0.92);
    --footer-bg:    rgba(246, 248, 250, 0.9);
    --shadow:       0 8px 32px rgba(31, 35, 40, 0.18);
    --shadow-sm:    0 2px 8px rgba(31, 35, 40, 0.12);
    --scrollbar-track: #f0f4f8;
    --scrollbar-thumb: #d0d7de;
}

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

html {
    height: 100%;
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    min-height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, sans-serif;
    background: var(--bg-gradient);
    background-attachment: fixed;
    color: var(--text);
    transition: background 0.3s ease, color 0.3s ease;
    -webkit-font-smoothing: antialiased;
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar            { width: 6px; height: 6px; }
::-webkit-scrollbar-track      { background: var(--scrollbar-track); }
::-webkit-scrollbar-thumb      { background: var(--scrollbar-thumb); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover{ background: var(--accent); }

/* =====================================================
   App Shell
   ===================================================== */
.app-shell {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

/* ---- Header ---- */
.app-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--header-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-sm);
    transition: background 0.3s ease, border-color 0.3s ease;
}

.header-inner {
    display: flex;
    align-items: center;
    padding: 0 2rem;
    height: 60px;
    gap: 0.25rem;
}

.header-brand {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    user-select: none;
    text-decoration: none;
    color: var(--text);
    flex-shrink: 0;
    transition: opacity 0.15s;
}

.header-brand:hover { opacity: 0.8; }

.brand-icon {
    font-size: 1.4rem;
}

.brand-title {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text);
}

.brand-online {
    color: var(--accent);
}

/* ---- Nav ---- */
.app-nav {
    margin-left: 0.5rem;
    flex: 1;
}

.nav-list {
    list-style: none;
    display: flex;
    align-items: center;
    gap: 2px;
    margin: 0;
    padding: 0;
}

.nav-link {
    display: block;
    padding: 0.4rem 0.75rem;
    border-radius: 6px;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 500;
    white-space: nowrap;
    transition: background 0.15s, color 0.15s;
}

.nav-link:hover,
.nav-link:focus {
    background: var(--accent-dim);
    color: var(--text);
    outline: none;
}

/* ---- Hamburger ---- */
.nav-hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 36px;
    height: 36px;
    padding: 6px;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 6px;
    cursor: pointer;
    margin-left: auto;
    flex-shrink: 0;
}

.nav-hamburger span {
    display: block;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: transform 0.2s, opacity 0.2s;
}

.nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.open span:nth-child(2) { opacity: 0; }
.nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.theme-toggle {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.9rem;
    background: var(--accent-dim);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s, transform 0.1s;
}

.theme-toggle:hover {
    background: var(--accent-dim);
    border-color: var(--accent);
    transform: translateY(-1px);
}

.theme-toggle:active {
    transform: translateY(0);
}

.theme-icon {
    font-size: 1rem;
}

/* ---- Main content ---- */
.app-main {
    flex: 1;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 2.5rem 1rem 3rem;
}

/* ---- Footer ---- */
.app-footer {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 2rem;
    height: 44px;
    background: var(--footer-bg);
    backdrop-filter: blur(8px);
    border-top: 1px solid var(--border);
    font-size: 0.78rem;
    color: var(--text-muted);
    transition: background 0.3s ease;
}

.app-footer a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s;
}

.app-footer a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* =====================================================
   Form Card
   ===================================================== */
.form-card {
    width: 100%;
    max-width: 820px;
    background: var(--surface);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border);
    border-radius: 16px;
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: background 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.form-card-header {
    padding: 1.75rem 2rem 1.25rem;
    border-bottom: 1px solid var(--border);
    background: var(--surface-2);
}

.form-card-title {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.025em;
}

.form-card-subtitle {
    margin-top: 0.3rem;
    font-size: 0.875rem;
    color: var(--text-muted);
}

.form-body {
    padding: 1.75rem 2rem 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.4rem;
}

/* =====================================================
   Form Fields
   ===================================================== */
.field-group {
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
}

.field-group--inline {
    flex-direction: row;
    gap: 1rem;
    align-items: flex-end;
    flex-wrap: wrap;
}

.field-sub {
    flex: 1;
    min-width: 180px;
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
}

.field-label {
    font-size: 0.82rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
}

.field-textarea,
.field-input,
.field-select {
    width: 100%;
    padding: 0.7rem 0.9rem;
    background: var(--surface-2);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text);
    font-size: 0.9rem;
    transition: border-color 0.2s, box-shadow 0.2s, background 0.3s;
    outline: none;
}

.field-textarea {
    font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
    font-size: 0.85rem;
    resize: vertical;
    line-height: 1.6;
}

.field-textarea--result {
    background: var(--surface);
    color: var(--accent);
    cursor: default;
}

.field-textarea:focus,
.field-input:focus,
.field-select:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px var(--accent-dim);
}

.field-select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%238b949e' d='M6 8L0 0h12z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.75rem center;
    padding-right: 2.2rem;
}

.field-select option,
.field-select optgroup {
    background: #1c2128;
    color: #e6edf3;
}

/* =====================================================
   Action Buttons
   ===================================================== */
.action-buttons {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.65rem 1.6rem;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    letter-spacing: 0.02em;
    transition: background 0.2s, transform 0.1s, box-shadow 0.2s, opacity 0.2s;
}

.btn:active {
    transform: translateY(1px);
}

.btn:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    transform: none;
}

.btn--primary {
    background: var(--accent);
    color: #fff;
    box-shadow: 0 2px 8px rgba(88, 166, 255, 0.25);
}

.btn--primary:hover:not(:disabled) {
    background: var(--accent-hover);
    box-shadow: 0 4px 14px rgba(88, 166, 255, 0.4);
    transform: translateY(-1px);
}

.btn--secondary {
    background: var(--btn-secondary-bg);
    color: var(--accent);
    border: 1px solid var(--btn-secondary-border);
}

.btn--secondary:hover:not(:disabled) {
    background: var(--accent-dim);
    border-color: var(--accent);
    transform: translateY(-1px);
}

/* =====================================================
   Copy Button
   ===================================================== */
.result-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.btn-copy {
    padding: 0.3rem 0.85rem;
    font-size: 0.8rem;
    font-weight: 600;
    background: var(--accent-dim);
    color: var(--accent);
    border: 1px solid var(--border);
    border-radius: 6px;
    cursor: pointer;
    transition: background 0.2s, border-color 0.2s, color 0.2s;
    letter-spacing: 0.02em;
}

.btn-copy:hover {
    background: var(--accent-dim);
    border-color: var(--accent);
}

.btn-copy--success {
    background: rgba(46, 160, 67, 0.15);
    color: #3fb950;
    border-color: rgba(46, 160, 67, 0.4);
}

/* =====================================================
   Error Banner
   ===================================================== */
.error-banner {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    padding: 0.75rem 1rem;
    background: var(--error-bg);
    border: 1px solid var(--error-border);
    border-radius: 8px;
    color: var(--error-text);
    font-size: 0.88rem;
    font-weight: 500;
    animation: slideDown 0.2s ease;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-6px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* =====================================================
   Spinner
   ===================================================== */
.spinner {
    width: 14px;
    height: 14px;
    border: 2px solid rgba(255,255,255,0.3);
    border-top-color: #fff;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    flex-shrink: 0;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* =====================================================
   Blazor Error UI
   ===================================================== */
#blazor-error-ui {
    display: none;
    position: fixed;
    bottom: 1.5rem;
    left: 50%;
    transform: translateX(-50%);
    background: var(--surface-2);
    border: 1px solid var(--error-border);
    border-radius: 10px;
    padding: 0.8rem 1.25rem;
    color: var(--error-text);
    font-size: 0.875rem;
    box-shadow: var(--shadow);
    z-index: 1000;
    gap: 0.75rem;
    align-items: center;
}

#blazor-error-ui .reload {
    color: var(--accent);
    text-decoration: underline;
    cursor: pointer;
    margin-left: 0.5rem;
}

#blazor-error-ui .dismiss {
    cursor: pointer;
    margin-left: 0.75rem;
    opacity: 0.7;
}

#blazor-error-ui .dismiss:hover {
    opacity: 1;
}

/* =====================================================
   Responsive
   ===================================================== */
@media (max-width: 768px) {
    .nav-hamburger { display: flex; }

    .app-nav {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--header-bg);
        backdrop-filter: blur(12px);
        -webkit-backdrop-filter: blur(12px);
        border-bottom: 1px solid var(--border);
        padding: 8px 1.5rem 12px;
        margin-left: 0;
    }

    .app-nav.open { display: block; }

    .nav-list { flex-direction: column; align-items: stretch; gap: 2px; }

    .nav-link { width: 100%; }
}

@media (max-width: 640px) {
    .header-inner { padding: 0 1rem; }
    .app-footer  { padding: 0 1rem; }
    .app-main    { padding: 1.25rem 0.75rem 2rem; }
    .form-card   { border-radius: 12px; }
    .form-card-header { padding: 1.25rem 1.25rem 1rem; }
    .form-body   { padding: 1.25rem 1.25rem 1.5rem; }
    .brand-title { font-size: 1.05rem; }
    .theme-label { display: none; }
    .field-group--inline { flex-direction: column; }
}